The Skin, and nails, By: Kareema Ameene Husein Al-Khafaji M.B.Ch.B., D.V.D., MSc. University of Babylon, College of Medicine. Printed on Microsoft word Introduction The skin is the largest organ of the human body, it covers an area of approximately 2m² and weights 4kg, it is not as usually supposed merely an external covering, but a complex structure, sophisticated vital organ consisting of a number of layers and tissue component ( fig.1,2,3),with many important functions (Box.1).

Fig. 1

Fig.1.The epidermis, which functions both to protect the underlying Structures and to participate in inflammatory processes. Epidermal cells are constantly involved in the keratinization process, so that the entire normal epidermis is replaced approximately every 28 days and the spent stratum corneum cells are lost to the environment.

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Fig. 2 skin with out hair (Palm or sole) Fig. 3 skin with hair 2

Box 1 Functions of the human skins

Function Structure/cell involved protection against; chemical, particle horny layer ultraviolet radiation melanocytes antigens, haptens, microbes Langerhans cells Preservation of a balanced internal horny layer environment. Prevent loss of water, electrolyte horny layer and macromacules. Shock absorber dermis and subcutaneous fat Temperature regulation blood vessels + eccrine sweat glands Insulation subcutaneous fat Sensation specialized nerve endings Lubrication sebaceous glands Protection and prising nails Calorie reserve subcutaneous fat Vitamin D synthesis keratinicyte Body odour/pheromones Apocrine sweat glands Psychological display skin, lips, hair and nails

Skin is a mirror of the internal body organ, its examination reflects a lot of internal diseases, so the physician must has a good knowledge in dermatology to diagnose the common skin diseases as well as the skin manifestations of internal organs such as; thyrotoxicosis, hypothyroidism, acromegaly , Addison disease, diabetes mellitus , leprosy, ulcerative colitis, internal malignancy,..etc.with naked eye, but one should suggested that “what the mind dose not know, the eyes cannot see” .So dermatology is a visual clinical specialty. The accurate diagnosis of most skin lesions requires an adequate history, careful examination of the patient preferably in a natural light, some times magnifying lens is useful and occasionally, laboratory investigations might be needed.

The out line of an approach to dermatologic diagnosis:

1-Epidemiology and Etiology; Age, sex, race, occupation, address. 11-History of present ; A-Duration of onset of skin lesions in: days, weeks, months, years. B-Site of onset, details of spread. C-Exacerbating factors like relation ship of skin lesions to; season, heat, cold, drug ingestion, alcohol intake, occupation, hobbies, exposure to 3 irritants, effects of mense, and pregnancy. D-Skin symptoms: itch, burning, pain, paresthesia. E-Constitutional symptoms; 1-“Acute illness” syndrome: headaches, chills, fever, weakness. 2-“Chronic illness”syndrome: fatigue, weakness, anorexia, wheight loss, malaise. F-Past history of skin disorders G-past general medical history inquires specifically about asthma and hay fever. H-Family history of skin disorders; if positive-inherited, infection/infestation. I- Family history of medical disorders. J- Drugs used to treat present skin condition; topical, systemic, physician Prescribed? , patient initiated? K- Drugs prescribed for other disorders (including those taken before onset of Skin disorder). L-Systemic review. III.Physical Examination; A-Appearance of patient; -uncomfortable, toxic, well, intelligence and educational level. -Signs of anemia, jaundice, and cyanosis. -Features of hyperlipidaemia and endocrine diseases like; acromegaly, Cushing syndrome, Addison disease, thyrotoxicosis, or hypothyroidism -Deformities, swellings, buffeness of the eyes. B-Vital signs; temperature, pulse, respiratory rate and blood pressure. C- Examination of skin in which four major skin signs should be noted: (1) type, (2) shape, (3) arrangement, (4) distribution of lesions. 1-Type of lesions (Box 2) Primary skin lesions, secondary skin lesions, special skin lesions:

(Box 2) primary skin lesions

Lesion definition and examples

Erythema: is redness caused by vascular dilatation. Macule: non-palpable area of altered color of skin; may be red, hypopigmen, depigmented, hyperpigmented or blue. Examples; Vitiligo, melasma, Tinea versicolor. Papule: palpable elevated small area of skin (less than 0.5 cm) in diameter. It is produced by proliferation of tissue cells or infiltration with the inflammatory cells. Example . A papule of (1-2mm.) in diameter in size is called micropapulue like keratosis pilaris.A papilloma is a nipple-like projection from the skin like filiform wart. Plaque: is an elevated area of skin greater than 2cm. in diameter but with out substantial depth .Example; psoriasis. 4 Nodule: is a solid mass in the skin, usually greater than 0.5cm. in diameter, in both width and depth, which can be seen to be elevated or can be palpated. Example boile. Tumour: is hard to be defined as the term is based more correctly on microscopic pathology than on clinical morphology. We keep it here as a convenient term to describe an enlargement of the tissues by normal or pathological material or cells that form a mass, usually more than cm. Because the word„tumour‟ can scare patients, tumour may courteously be called „large nodules‟ especially if they are not malignant, example lipoma. Vesicle: is a circumscribed elevation of skin, less than 0.5cm. and containing fluid. example; herpes simplex. Bulla: is a: is a circumscribed elevation of skin, less than .5cm. and containing fluid. example elevation of skin, more than 0.5cm. and containing fluid. example; pemphigus vulgaris. Pustule: is a circumscribed collection of leukocytes and free fluid in the skin varies in size examples: , . Abscess: is a localized collection of pus in a cavity, more than 1cm in diameter. Wheal: Sudden exudation of fluid in the superficial dermis producing a flat raised area of any size and often with an orange-peel appearance on the surface; they are transient and may last only a few hours. It is a primary lesion of urticaria and can be seen in insect bits, dermographism. Angioedema: is a diffuse swelling caused by oedema extending to the subcutaneous tissue. Petechiae: are pinhead-sized macules of blood in the skin. Purpura: Circumscribed deposit of blood in the skin of more than0.5cm in diametr.Example of both Cutaneous vasculitis, senile purpura, gonococcemia. Haematoma: is a swelling from gross bleeding.

Box 3.Secondary Skin lesions Secondary lesions develop during the evolutionary process of skin disease or are created by scratching or infection. They may be the only type of lesion present in which case the primary disease process must be inferred. Secondary skin lesions are: - Skin lesion Definition and examples (e.g.) Scales: excess dead epidermal cells that are produced by abnormal keratinization and shedding.e.g. Psoriasis, tinea versicolor, pityriasis rosea. Crusts: a collection of dried serum and cellular debris e.g. impetigo, atopic dermatitis (face). Erosions: A focal loss of epidermis; they do not penetrate below the dero- epidermal junction and there fore heal with out carring.e.g.Candidiasis ,intertrigo, vesiculo- bullous disease. Ulcers: A focal loss of epidermis and dermis, they heal with scarring e.g.Aphthus, chancroid, and primary chancre. 5 Fissure: A linear loss of epidermis and dermis with sharply defined, nearly vertical walls e.g. chapping (hands, feet), intertrigo, chronic eczema (fingertip). Atrophy: depression in the skin resulting from thinning of the epidermis or dermis e.g. striae. Scar: Abnormal formation of connective tissue implying dermal damage, when following injury or surgery, they are initially thick and pink but with time become white and atrophic (e.g. burn, acne). Atrophic scar remains below the surface; hypertrophic scar is raised above the surface, while a keloid grows beyond the limits of original lesion. Lichenification: A diffuse thickening of skin, hyperpingmentation and accentuation of skin lines with sever itching It is seen in:1-Neorodermatitis2-psoriasis 3-Atopic dermatitis 4-Chronic zinc deficiency. Excoriation: Scratching leading to the removal of the top of a lesion or even the skin other wise. Sinus: is a cavity or channel that permits the escape of pus or fluid. Striae: (streach mark): is a streak-like linear atrophic pink, purple or white lesion of the skin caused by changes in the connective tissue. Box 4.Special Skin Lesions: Skin lesion Definition and examples Comedone: A plug of sebaceous and keratinous material lodged in the opening of hair follicle; the follicular orifice may be dilated (black head) or narrowed or closed head (white head).It is a primary lesion of acne vulgaris. Milia: A small, superficial keratin with no visible opening. Cyst: Circumscribed lesion having a wall and a lumen; the lumen may contain fluid. Burrow: A narrow, elevated, tortuous channel with some scaling caused by scabies parasite. Telangiectasia is a visible dilatation of small cutaneous blood vessels e.g.; lupus erythematosus, , xeroderma pigmentosum. Poikiloderma: is a combination of atrophy, reticulate hyperpigmentation and telangiectasia. Color of lesions or of the skin if diffuse involvement as fallows (table 1):

Skin color the disease Red Erythem Hypopigmented pityriasis alba Skin colored Pla n wart Depigmented Vitiligo Violaceous Lichen planus Blue Mongolian spot, tattoo Orange Xanthoma Table 1 show the relation of skin color & the lesion 6

Note: The distinction between red or purpuric lesion that; the purpura dose not Blanch with pressure (Dias copy). Palpation to fell the -presence of tenderness -deviation of temperature (hot, Cold). –consistency (soft, firm, hard, fluctuant, board like). -Mobility -estimate the depth of lesion (i.e. dermal or subcutaneous). 2-Shape of individual lesions; Round, oval, polygonal, polycyclic, iris, umblicated 3-Margination: well-defined (can be traced with the tip of a pencil), ill-defined. 4-Arrangement of multiple lesions: (Box.5).

Box.5. Configuration of the lesions Arrangement definition Linear: Lesions situated along a line, e.g.linear lesion in patient with Psoriasis. Grouped: collection of lesions together, e.g. .herpes simplex. Circinate: Lesion tending to form a circle, tinea corporis. Arcuate: means curved, e.g. tinea cruris. Discoid (nummular): means round or disc like, e.g. discoid eczema. Gyrate: means wave like. Retiform and reticulate: mean net-like. Disseminated: scattered, discrete lesion or diffuse involvement (i.e. with out Identifiable border).

5-Distribution of lesions: Extent: isolated (single lesions), localized, regional, generalized, universal. Pattern:(Box 6)symmetrical or a symmetrical. Symmetry often implies an internal causation, where as a symmetry implies external causation. Is the eruption Centrifugal or centripetal? certain common skin diseases such as chicken pox and pityriasis rosea are characteristically centripetal where as erythema multiforme and erythema nodosum are centrifugal. Is the disease exhibit mainly on flexor areas of the body like atopic dermatitis and lichen planus? or extensor area as in plaque type of psoriasis? Are only sun exposed areas affected (face-shaped area of the neck, extensors of hands, forearms, feet, and legs) affected that implicating sun light or some other external causative factor? if at the site of pressure, as in corn or planter warts, intertrigenous areas (seborrhoeric dermatitis), follicular localization (folliculitis) or random distribution. localized distributions may point immediately to an external contact as for example; contact dermatitis from gloves, shoes, nickel ear rings, lip stick dermatitis, etc... Swelling of the eye lids may indicates the presence of the lesion in the forehead like boil or insect bite or in the scalp like allergic contact dermatitis from hair dye. Dermatomyositis often produces swelling and heliotropic erythema of the eyelids, with out scaling of the skin. A localized area of hypo pigmentation in the face of the child with mild scaling indicated pityriasis alba, while a depigmented patch with slightly raised edges, anesthetic to pin-prick testing, cooler than body temp. 7 is seen in tubercloid leprosy (Hansen‟s disease). (Fig. 4). while the patch of depigmentation with normal sensation and temperature is seen in vitiligo (Fig.5 ),

Fig. 4 .Tubercloid leprosy Fig.5. Vitiligo at site of Iraqi futa As a Koebner phenomena. (Box 6).The pattern of lesions ------Pattern definition

Symmetrical: when the lesions are on almost mirror image of each other on the two halves of the body.

Segmental: when the lesions are situated in a limited area confirming to a neural segment (dermatomal distribution).

Unilateral: when the lesions are situated only on one side of the body and stop at mid line.

Bilateral: when the lesions are situated on both the halves of the body.

Geographical: when the lesion forms an irregularly shaped area.

The presence of hypopigmented, hyper pigmented and or red scaly macules and or patches on the neck and upper trunk of a young adults indicates pityriasis versicolor (Fig. 6,7).

Fig.6. Pityriasis versicolor-see Fig.7.Pityriasis versicolor. See Brown scaly macules. Hypopigmented macules in upper Back. & Becker nevus hyperpig -pigmentation on one side of the back

8 Characteristic patterns: certain disease has especial characteristic patterns like; secondary syphilis, atopic dermatitis, acne, erythema multiforme, candidiasis, lupus erythematosus, pemphigus, pemphigoid, porphyria cutanea tarda, xanthoma, necrotizing angitis (vasculitis), scarlet fever, herpes zoster, varicella, Staphylococcal scalded- skin syndrome, toxic epidermal necrolysis, Kaposi sarcoma. D- Hair and nails HAIR; examination of scalp to see if there is ? Scalp involvement by the disease e.g. .; psoriasis or discoid lupus erythematosus? This involvement is it localized or generalized? extends beyond the scalp, involves the ear? The density hair should also be assessed in the scalp and other part of the body like eye brows and eye lashes. So if there is hair loss ‹alopecia› ﴾table ﴿, alopecia should be assessed if it is localized, generalized and in both if it is scarring or non-scaring? if still the presence of inflammatory reactions? Or follicular plugging? In case of female androgenic syndrome patient has androgenic alopecia as well as acne vulgaris, hisutism and melasma. Nails; should be examined carefully. The structure of the and nail bed is shown in (Fig.8).

Fig.8. Normal nail The nail has several distinct anatomic areas. The hard nail plate emerges from a matrix of specialized epithelial cells. The matrix begins 7 to 8 mm under the proximal nail fold, and its distal end is the white crescent called the lunula. The richly vascularized nail bed lies directly beneath the plate to provide adherence and support and is the basis of the characteristic pink color. The proximal and lateral nail folds surround the plate on three sides, and the cuticle, an outgrowth of the proximal fold, provides a seal between the fold and the nail plate. Examination of the nail includes; the nail folds to see if there is acute (acute ) (Fig.9), chronic inflammation (chronic paronychia) (Fig.10) and examination of the nail plate to see ; the brittleness, discoloration, pitting,

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Fig.9.Acute paronychia. Fig. 10.Chronic paronychia , shedding,(with or without scarring),splitting, thinning, striation, ptyergium, koilonychias,hypertrophy,or splinter hemorrhage,subangualfibroma(Fig.11).

Fig.11. periungual fibroma E. Mucus membranes; Examination of mouth and throat; is conducted with the patient sitting up either in bed with the head resting comfortably back on pillows, and a pair of latex gloves are essential. The lips, teeth, gums, tongue, palate fauces and oropharynx are then visualized systemically, and finally mouth and tonsillar regions is carried out. Examination of female genitalia; women are best examined in the lithotomy Position. Examine the perineum, vulva and labia majora and minora for; Discharge, redness, swelling, excoriations, ulcers, warts, depigmentation, scarring, and other lesions. Also male genitalia should be examined. (Gloves should be worn if genital infection is suspected), to cheek the presence of ; warts, ulcers (Box. 7 ),burrows and excoriated papules in the shaft of penis ( scabies), circinate palanitis of Reiter‟s disease, and of the symmetry and any abnormalities in the testes, or epididymis and spermatic cord. As well as anorectal examination should be done perfectly. (Box 7 ).Causes of genital ulcers:

A-Sexually transmitted diseases: B- Non-sexually transmitted disease 1-Sexual trauma 1-Fixed drug eruption 2-primary syphilis 2-Behcet disease 3-Cutaneous manifestations of secondary 3-erosive balanits syphilis. 4-benign and malignant tumor of 4-herpes progenitalis genital area. 5-chancroid 6-scabies. 5-herpes zoster. 7-gummatous ulceration of tertiary syphilis 6-T.B. of skin. 8-lymphogranuloma venerium 9-granuloma inguinal. 10 F-General medical examination. IV Differential diagnosis V.Laboratory and special examination. Special Clinical and Laboratory Aids to Dermatologic Diagnosis Special Technique used in Clinical Examination: 1- Magnification with hand lens: To examine lesions for fine morphologic detail, it is necessary to use a magnifying glass (hand lens) (7X). Magnification is especially helpful in the diagnosis of lupus erythematosus to see (follicular plugging), lichen planus (Wick-ham‟s striae), basal cell carcinoma (translucence and telangiectasia), and malignant melanoma (subtle change in color especially grey or blue). Application of a drop of mineral oil on the lesion on the presence of a good light, the hand lens will give a magnification of 10X to 30X (dermatoscope). 2- Wood‟s lamp (black light) is valuable in the diagnosis of certain skin and and of porphyria. Long-wave ultraviolet radiation can be obtained by fitting a high-pressure mercury lamp with a specially compounded filter made of nickel oxide and silica (Wood‟s filter); this filter is very opaque to all light except for a band between 320 and 400 nm. When the ultraviolet emitted by wood‟s lamp (360nm) impinge on the skin, fluorescent pigment and subtle color differences of melanin pigment can be visualized. Wood‟s lamp is particularly useful in the detection of the fluorescence of : A-Some infection like dermatophyte infection in the hair shaft (green to yellow due to the presence of Microsporum species. Trichophyton species do not fluorescence), and of: Tinea versicolor (dull yellow), erythrasma (coral red), and pseudomonas infections (green). B- A presumptive diagnosis of porphyria can be made if a pinkish red fluorescence is demonstrated in urine examined with Wood‟s lamp; addition of diluted hydrochloric acid intensifies the fluorescence. C- Helps to estimate variation in the lightness of lesions in relation to the normal skin color in both dark-skinned and fair-skinned peoples; e.g. Tinea versicolor and Ash leaf hypopigmented Macule in tuberous sclerosis are hypomelanotic and are not as white as the lesions seen in vitiligo which are amelanotic. So you can differentiate between hypopigmentation and depigmentation. In patients with hyperpigmentation it is used to localized the site of the pigmentation since it accentuates epidermal pigmentation as in freckle and melasma ( looks darker under Wood‟s light), while dermal pigmentation is unchanged like Mongolian sacral spot (looks the same). This, however, is more difficult or not possible in patients with brown skin. 3- Diascopy: Consist of firmly pressing a microscope slide over a skin lesion. The examiner will find the procedure of special value in determining whether the red color of a macules or papule is due to capillary dilatation (erythema) or to extravasations of blood (purpura) that does not blanch. Diascopy is also useful for the detection of the glassy yellow-brown appearance of papules in tuberculosis of the skin (lupus vulgaris gives apple-jelly appearance), Sarcoidosis, lymphoma, and granuloma annular. 11 4- Aceto whitening facilitates detection of subclinical penile warts. Male partners of females with genital warts may also be infected. Gauze saturated with 5% acetic acid (white vinegar) is wrapped around the penis or placed between the labia. After 5 to 10 minutes the penis or vulva is inspected with a 10X hand lens warts appear as small white papules. Clinical tests: 1- Auspitz‟s sign is “positive” when slight scratching or curetting of a scaly lesion reveals punctuate bleeding points with the lesions. This suggests psoriasis, but it is not specific. 2- Darier‟s sign: is positive when a palpable wheal appear after a vigorous rubbing (with the blunt end of an instrument such as pen or key) of the brown macular or a slightly papular lesion of urticaria pigmentosa (mastocytosis). The wheal may not appear for 5-10 minutes. 3- Patch testing is used to document and validate a diagnosis of allergic contact sensitization in order to identify the causative agent. It also may be of value as a screening procedure in some patients with chronic or bizarre eczematous eruption (e.g. hand and foot dermatosis). Substances to be tested are applied to the skin in shallow cups (Finn chambers) fixed with a tape and left in place for 24 to 48 hours. Contact hypersensitivity will result in a papular-vesicular reaction that develops within 48 to 72 hours. When the test is read putting in mind that the patient should not be on oral steroid. 4- Photo patch testing is a combination of patch testing and UV irradiation of the test site and is used to document photo-allergy. Microscopic Examination of Scales, Crusts, Serum and Hair 1- Microscopical examination for fungus infection. The highest rate of recovery of organisms occurs in specimens taken from the tops of vesicles and the active edges of a lesion. The site should be swabbed with an alcohol pad or water and scraped with a # 15 blade, or the roofs of vesicles are snipped off with scissors. The moist corneocytes are then easily transferred from the blade to a glass slide. One or two drops of 10-20% aqueous potassium hydroxide solution added to the specimen and covered with a cover slip and left 30 minutes to clear or gently warmed but not boiled. It is then examined under the light microscope with the 8mm or 4mm objective using low illumination. The mycelia are recognized as branching refractile threads which boldly transgress the outlines of the squamous cells. (Fig.12).

Fig.12. The mycelia are recognized as branching refractile threads

12 Nails are examined in much the same way but it is necessary to break up the snippings and into small fragments. These are either heated in potassium hydroxide or are left to clear in it overnight before being examined. A scalp lesion is cleaned with 70% alcohol or with 1% cetrimide. Infected stumps and scales are removed by scraping with a scalped and put on glass slide. The infected are cleaned in potassium hydroxide in the same way as skin scales. Examination under the microscope reveals spores on the outside of the hair roots, and mycelia inside the hair substances. The Confirmation of the diagnosis and the species of fungus responsible can be established by culture on dermatophyte test media or sabouraud‟s dextrose agar (with or without antibiotics and cyclohexamide that added to suppress bacterial contaminants and yeasts). The easily broken infected hairs are embedded in the culture media in which two weeks or more are needed for the fungus to grow. 2-Gram stains and cultures of exudates and of tissue minces should be made in lesions suspected of being bacterial or yeast (Candida albicans) infections. Ulcers and nodules requires a scalped biopsy in which a wedge of tissue consisting of all three layers of skin is obtained; the biopsy specimen is put in a sterile tube and is then cultured for bacteria (including typical and a typical Mycobacterium) and fungi in a specific media accordingly. 3-Microscopic examination of cells obtained from the base of vesicles (T Zanck preparation) may reveal the presence of acantholytic cells in the acantholytic diseases (e g. pemphigus or SSS syndrome) or of giant epithelial cells and multinucleated giant cells (containing 10 to 12 nuclei) in herpes simplex, herpes zoster, and chicken pox. An intact vesicle (blister) is opened along one side, the roof folded back, and the underside gently scraped. The material obtained by gentle curettage with a scalpel is smeared on a glass slide, allowed to air-dry, and stained with either Sedi-stain, Giemsa‟s stain, Wright‟s stain or methylene blue, and examined to determine whether there are acantholytic (which are rounded with either cytoplasmic contents at the periphery in pemphigus vulgaris (Fig.13 ). Or giant epithelial cells (show typical multinucleated giant cells of herpes simplex) (fig.14). Culture of herpes simplex is now easily available.

Fig.13. acantholytic cells Fig.14. giant epithelial cells of of pemphigus vulgaris. herpes simplex.

4-Laboratory diagnosis of scabies The diagnosis of scabies is usually considered clinically in a patient with sever intractable generalized itching with the skin rash in the form of papules or papulo- vesicles and excoriations distributed in characteristic locations; on the flexor aspects 13 of the wrists in the finger webs, anterior axilla areola of breast in female, and on the buttocks and genitalia (fig.15 ), the diagnosis is established by identification of the mite, or ova or feces, in skin scrapings removed from the papulovesicles or burrows (see fig.16). The burrow, a unique lesion, is a linear or serpiginous elevation of skin in the form of a ridge, 0.5 to 1.0 cm in length. These occur on the anterior surface of the wrists, in the webs of the fingers, or on the ulnor border of the hand. If burrows are not present, select a papule or the roof of a vesicle on the hand. The mineral oil technique is excellent for isolating the mite. Using sterile scalped blade on which a drop of sterile mineral oil has been placed, apply oil to the surface of the burrow or papule. Scrape the papule or burrow vigorously (about six times) in order to remove the entire top of the papule; tiny flecks of blood will appear in the oil. Transfer the oil to a microscopic slide and examine for mites, ova and feces. The mites are 0.2 to 0.4mm in size and had four pairs of legs (see fig.17, 18).

Fig.15 scabies Fig.16 burrows with sarcopets Scabiei (female), eggs and feces

Fig.17sarcopets Scabiei female. Fig.18 Scabies. Characteristic linear burrows in a typical location.

5-Skin biopsy Biopsy (from the Greek bios meaning „life‟ and opsis „sight‟) of skin lesions is useful to establish or confirm a clinical diagnosis. A piece of tissue is removed surgically for (histopathology, immunofluorescence, electron microscopy) and some tissues for other tests (e g. culture for organisms). When used selectively, a skin 14 biopsy can solve the most perplexing problem but, conversely, will be unhelpful in conditions without a specific histology (e g. most drug eruptions, pityriasis rosea, reactive erythema). Selection of the site of the biopsy is based primarily on the stage of the eruption and early lesions are usually more typical; this is especially important in vesiculo-bullous eruptions (e g. pemphigus, herpes simplex), in which the lesion should be no more than 24hours old. However, older lesions (2 to 6 weeks) are often more characteristic in discoid lupus erythematosus. There are many types of skin biopsy:  Punch biopsy: a small tubular knife is used to remove 3.0 to 4.0mm cuts of epidermis and subcutaneous tissue in a cork screw movements between the thumb and index finger (fig.19), then the base is cut off with scissors.

Fig. 19 Punch biopsy  Incisional biopsy: When just part of a lesion is removed for laboratory examination or  Excisional when the whole lesion is cut out especially when the lesions are small (up to 0.5cm diameter) but incisional biopsy is chosen when the partial removed of a larger lesion is adequate for diagnosis, and complex removed might leave an unnecessary and unsightly scar. Ideally, an incisional biopsy should include a piece of the surrounding normal skin specimen. For light microscopy should be fixed immediately in buffered neutral formalin, label the specimen container with patient‟s name, age, sex, site of the biopsy and the time is taken. Provide the pathologist with detailed summary of the clinical history, description of the lesions and differential diagnosis and better to discus the results with the pathologist.  Shave biopsy: indicated in;-benign superficial epidermal lesions e.g. seborrhoeric keratosis, actinic keratosis. – Benign intradermal naevi may be . ﴿partially removed ﴾ Fig.20

Fig. 20 Shave biopsy 15 The hair The hair (trichos), is epithelial in origin and is made of modified horn cells, and arises in a follicle formed of invaginated epidermal cells, situated in the deeper parts of the dermis. Each hair is made up of the three parts: ﴾a﴿ an outer layer, named cuticle, made up of flattened horny cells, ﴾b﴿ the cortex being a thick pigmented layer of spindle shaped cells, ﴾c﴿ the medulla extending only for a variable distance up the shaft from the papilla, and is made up of a column of nucleated cells (fig.21) . hairs have no medulla. A small band of unstriated muscle is encroached to the hair follicle and forms the arrector pili muscle.

Fig.21 Hair bulb. This a complex structure composed of several distinct layers of structures. The papilla is engorged with blood vessels, and the germinative cells, which are among the most metabolically active in the body, lie close by. The hair shaft, which is completely keratinized and without living cells, lies just to the hair bulb. There are three types of hair: 1-Lanugo hairs. Fine long hairs covering the fetus, but shed about one month before birth. 2-Vellus hairs. Fine short unmedullated hairs covering much of the body surface. They replace the lanugo hairs just before birth. 3-Terminal hairs. Long coarse medullated hairs, and this subdivided into; [a] scalp hairs, [b] sexual hairs. Sexual hairs developed after puberty [under effect of androgen hormone] on the pubic area and axilla in female, and on the pubic area, axilla, face chest, abdomen and extremities of males. Any disease of pituitary or adrenal glands will affect the distributions of this type of hair. The hair cycle: Each follicle passes, independently of its neighbors, through regular cycles of growth and shedding. There are three phases of follicular activity (Fig.22). 1-Anagen.The active phase of hair production. 2-Catagen.A short phase of conversion from active growth to the resting phase. Growth stops and the end of the hair become club-shaped. 3-Telogen.A resting phase at the end of which the club hair is shed. The duration of each of these stages varies from region to region. On the anagen lasts for about 1000days, catagen for about 10days and telogen for about 100days. As many as 100hairs may be shed from the normal scalp every day as a normal consequence of cycling. The proportion of hairs in the growing and resting stages can be estimated by looking at plucked hair (a trichogram), on the scalp, about 85% are 16 normally in anagen and 15% in the telogen phase. The length of hair is determined by the duration of anagen; e.g. the hairs of the eye brows have shorter cycles than those of the scalp. Each hair follicle goes through its growth cycles out of phases with its neighbors, so there is no molting period. However, if many pass into the resting phase (telogen) at the same time, (due to any cause like; fever, haemorrhge, anemia surgery, severs psychological truma, etc) then a corresponding large number will be shed 100days later (this is called ).There are important racial differences in hair. Asians tend to have straight hair, Negroid woolly hair, and Europeans wavy hair. Mongoloids have less facial and than Mediterranean people who also have more hair than Northern Europeans.

Fig. 22 Phases of the hair cycle. Anagen is the growing portion of the hair Cycle, and hairs such as those of the scalp may remain in this phase for many years. At some predetermined time, the hair enters a short-lived interphase (catagen), followed by the resting or telogen phase, in which the hair is shed as a club hair. Alopecia: means hair loss .It is divided into localized or generalized and both of the could be classified into non-scarring in which regrowth of hair will occur and scarring in which there is permanent loss of hair due to destruction of hair follicles by many diseases(Box 8 ). (Box 8).Causes of hair loss (alopecia) Causes of Localized hair loss:

A – non-scarring B- Scarring alopecia: 1-Traumatic alopecia; 1- Idiopathic. (a) Neonatal frictional alopecia 2-developmental defect and hereditary (b) Trichotillomonia disorders (c) Tractional alopecia 3-Physical injuries like Burn, (d) Pressure alopecia mechanical trauma, Radio dermatitis.

(e) Hot –comb alopecia 4-Infections like, carbuncle, tinea capitis 2- (kerion), and herpes zoster. 3-Tinea capitis (human origin) 5-Diseasesof unknown origin like 4-Post –pyogenic infection and discoid lups erythematosus secondary syphilis. scleroderma, sarcoidosis, necrobiosis auses of Diffuse hair loss; 6-cicatricial basal cell carcinoma 17 7-Pseudopelade. causes of Diffuse hair loss;

A- Non – scarring alopecia:- B- Diffuse scarring Alopecia:- 1- Androgenic alopecia: the loss of hair in both 1- Discoid lupus erythematosus sexes as follows; - In women is fronto - vertical 2– Radiotherapy hair thinning and in men is bitemporal and 3- vertical hair thinning. 4 – Lichen planus pilaris 2- Diffuse type of alopecia areata. 5-Sever extensive burn 3-Telogen effluvium (fevers, post labor 4-8 months, post major surgery and sever blood loss). 4- Metabolic and endocrine disorders: hypothyroidism, hyperthyroidism, hypoparathyroidism hypopituitraism and Disordersdiabetes mellitus.of the nails 5- Nutritional deficiency, especially iron deficiency. 6-Drugs induced especially antimetablic (), anticoagulant, excess vit. A., oral contraceptive.7-liver disease.

8- Sever chronic illness. 9 - HIV disease. The condition of the nails may reflect both local and systemic disease, and Omission of this part of the general examination could result in some important diagnostic clues being over looked .Fingernails grow about 1 cm every 3 months and toe nails at about one – third of this rate. Splinter hemorrhage: `these are fine linear dark brown flecks running longitudinally in the plate. They are most commonly to trauma but, they may be seen in psoriasis. They are also sign of bacterial endocarditis, SLE and rheumatoid arthritis. Onycholysis; Onycholysis is painless separation of the nail plate from nail bed (Fig. 23) due to many causes :-( 1) Dermatological disease; psoriasis, dermatitis, dermatophyte or Candidal infection. (2) Trauma (3) General medical conditions; impaired peripheral circulation, hypothyroidism and hyperthyroidism. (4)Hereditary partial onycholysis. (5) Drugs e.g. tetracycline + sunlight exposure.

fig.23 onycholysis

In case of recalcitrant and long lasting onycholysis you should think of:-

1-Post traumatic scar in the nail bed. 2-dermatophyte infection. 3-tumor of the nail bed and especially malignant melanoma (Nail pigment streak and pigmentation of the 18 posterior nail fold (Hutchinson‟s sign) is diagnostic of a melanoma affecting the nail matrix, with migration of pigment cells on the posterior nail fold and longitudinal nail biopsy through the streak will confirm the diagnosis).

Beau’s lines: These are transverse grooves which appear at the same time on all nails a few weeks after stress or acute illness that temporarily interrupt nail formation. The lines progress distally with normal nail growth and eventually disappear at free edge.

Spoon nails: Lateral elevation and central depression of the nail plate causes the nail to be spoon shaped; this is called koilonychias (fig. 24). Spoon nails are seen in normal children a and may persist lifetime without any associated abnormalities. It is also a sign of iron deficiency anemia and in 50% of patients with idiopathic hemochromatosis. The nail reverts to normal when the anemia is corrected.

fig. 24 Spoon nail Finger clubbing: Is a distinct feature associated with a number of diseases, but it may occur as a normal variant .The distal phalanx of fingers and toes are enlarged to a rounded bulbous shape. The nail enlarges and become curved, hard, and thickened. The angle made by the proximal nail fold and plate increase and approaches or exceeds 180 degrees and when both thumb nail put in contact will from open window while in normal it form classed window. Causes of finger clubbing; (1) Respiratory; bronchogenic carcinoma, asbestosis, suppurating lung disease (empyema, bronchiectesis, cystic fibrosis), fibrosing alveolitis. (2)Cardiac; cyanotic congenital heart disease, subacute bacterial endocarditis. (3)Gastrointestinal; ulcerative colitis, crohn‟s disease, celiac disease, biliary cirrhosis. (4)Endocrine, thyrotoxicosis (5) Familial. White spots or bands of the nail ( punctuate) White spots in the plate are a common finding ,which possibly result from cuticle manipulation or other mild from of trauma . The spots are bands appear at the, unula or appear spontaneously in the nail plate and subsequently disappear or grow out with the nail. Whitening of the nails Is a rare sign of hypoalbuminoemia, half-and-half nail (white proximally and red – brown distally) are seen in some patients with renal failure. Rarely, drugs (e.g. antimalarials) may discolor nails. Ingrown toe nail: Ingrown toenail is common; the large toe is most frequently affected, the nail pierces the lateral nail fold and enters the dermis, where it acts as a foreign body .The first signs are pain and swelling .The area of penetration becomes purulent and oedemalous as granulation tissue grows alongside the generating nail. Ingrown nails occur from lateral pressure of poorly fitting shoes, improper or excessive trimming of the lateral nail plate or after trauma. Differential diagnosis of butterfly erythema on the face :( Fig.25) 1-Discoid lupus erythematosus (DLE). 2-SLE. 3-Psoriasis. 4-Contact dermatitis. 5-Seborrhoeric dermatitis. 19 6- Lups vulgaris. 7-Necrobiosis lipoidica can give fascail lesions like DLE.

Fig.25 Discoid lupus erythematosus

Pruritus (itch) Pruritus is defined as sensation that provokes the desire to scratch and the scratch reflex is the removal of noxious agents from the body surface. Impulses carrying the sensation on the itch passing from the nerve endings in the region of the dermo-epidermal region along the sensory spinal nerves to the spino- thalamic tract and then to the thalamus and sensory cortex. These pathways are shared by the sensation of pain. To know the severity of itching depends on the history, aided by the presence or absence of signs of scratching and rubbing and excoriation, broken hairs and polished nails. The term Pruritus sometimes used when there is itching with no visible skin disease. Medical conditions that causes Pruritus: 1-Liver disease like cholestasis and hepatitis (elevated bile salt). 2-Chronic renal disease (secondary hyperparathyroidism and elevated plasma histamine). 3-Blood diseases especially iron deficiency anemia, polycythemia rubra Vera, lymphoma, leukemia. 4-Thyroid disease: thyrotoxicosis and hypothyroidism. 5-HIV infection. 6-Internal malignancy. 7-Psychogenic. Some skin disease causing itching 1-Scabies, pediculosis, and insect bits. 2-Contact and atopic dermatitis. 3-Lichen planus. 4-Dermatitis herpetiformis. 5-Toxic eruption 6-Fungal infection (e.g. pityriasis versicolor). 7-Pityriasis rosea. 8-Seborrhoeric dermatitis .9- Urticaria and dermographism 9- Asteototic skin. 10-Psoriasis. 11-Sun burn. Coarse feature of face is seen in 1-Hypothyroidism. 2-Lipoid protenosis 3-Leprosy. 4-Out – door workers. 5-Acromegaly. 6-Others Erythroderma:(fig. 26) is defined as erythema with or without scaling of almost all the body. Erythroderma may occur at any age and is associated with extreme morbidity and appreciable mortality. It may appear suddenly or evolve slowly.

Fig.26 erythroderma Fig.27erythrodermic psoriasis

20 The causes are: 1-Eczema; (contact, Atopic, seborrhoeric dermatitis). 2-psoriasis (fig. 27). 3-Drug eruption (gold, isoniazid) 4-Cutaneous T cell lymphoma (sezary syndrome) might progress to erythroderma. 5- Other causes include lichen planus. 6-Psoriasis like conditions (pityriasis rubra to pilaris). 7-Icthyosiform erythroderma.8-Pemphigus erythematosus. 9-Scabies. Complications of erythroderma: A-Erythrodermic patients may be systemically unwell with shivering due to loss of temperature control and pyrexia. B-The pulse rate is elevated and the blood pressure low due to volume depletion (due to increase skin blood flow). C-Peripheral edema is common finding consequent on the erythrodrma, low albumin (due to loss of protein from skin) and high output cardiac failure. D-Reduced barrier function due to abnormal stratum corneum (resulted in increased percutaneous water loss leading to dehydration). E-Associated gut changes (mild mal absorption) F-Anemia. G-Lymph nodes may be enlarged, either reactively, caused by the skin inflammation, or secondary to lymphatous infiltration.

Causes of Scaly scalp disorders: 1-Dandruff. 2-Psoriasis 3-seborrhaeic dermatitis 4-Contact dermatitis 5-Tinea Capitis only in children and old ages. 6-Atopic dermatitis affecting the scalp. 7-Neorodermatitis of scalp. 8- Discoid lupus erythematosus. 9-Exfoliative dermatitis 10-P.R.P. (Pityriasis rubra pilaris).

Common Cause of irritable papular skin Rash

1-Scabies 2-Insect bites 3-Atopic dermatitis 4-Contact dermatitis 5-Lichen planus 6-Dermatitis herpetiformis

The sudden wide spread scaly rash (papulo-squamous eruptions is due to: -

1 Pityriasis rosea 2-Lichen planus 3-Guttate psoriasis 4-Secondary syphilis 5-dermatitis(seborrhoeric & Atopic or contact) 6-Drug eruption 8-Pityriasis versicolor (tinea versicolor) .

Common causes of perioral hyperpigmentation

1-Friction. 2-Mild seborrhoeric dermatitis. 3-Phytophoto dermatitis. 4-Licking dermatitis. 5-Post inflammatory hyperpigmentation. 6-Lichen planus actinicus.

Common Causes of Hyperpigmentation of the Face

1-melasma 2-post inflammatory hyperpigmentation. 3-post frictional hyperpigmentation 4-phytophoto dermatitis. 5-Lichen planus actinicus.

21 Diffuse hyperpigmentation. (Hyper melanosis) of Skin 1- Post inflammatory hyperpigmentation. 2-Becker naevus. 3-Naevus spilus. 4-Café au lait spots. 5-Phytophotodermatitis. 6-Berloque dermatitis. 7-Xeroderma pigmentosum. 8-Endocrine disorders: Addison disease, acromegaly, Cushing syndrome, pregnancy, oral contraception, phaeochromocytoma, carcinoid syndrome, ACTH and steroid administration. 9-Drugs: some drugs which cause hyperpigmentation not invariably due to hypermelanosis alone but sometimes due to deposition of the .drug or it‟s metabolite, either of which may be complexed with melanin .e.g. chloroqine, minocycline, psoralens,clofazimine,arsenic…….etc. 10-ystemic disorders: chronic renal faller, hepatic faller, chronic infections, Anemia, vit A and D deficiency, mal absorption, neoplastic disease, lymphoma, macular amyloidosis and vagabonds. Vitiligo is an acquired condition affecting 1% of all races, in which circumscribed depigmented patches develop. Etiology; there is complete loss of melanocytes from affected patches. There may be a positive family history of the disorder especially in those with generalized vitiligo and this type may associated with autoimmune diseases such as diabetes mellitus and adrenal disorders and pernicious anemia. Trauma and sunburn may precipitate the appearance of vitiligo. Clinical features and types: -Segmental vitiligo: is restricted to one part of the body but not necessarily a dermatome. -Generalized vitiligo: is often symmetrical and frequency involves the hand, wrists, knees and neck, as well as of the area around the body orifices. -The hair of the scalp and (Grey hair) may also depigment. -Complete universal type: all the skin becomes depigmented except small normal areas on the face. -Halo naevus: Formation of white depigmented ring around pigmented melanocytic naevus. -Ocular type (changing in the color of the eyes). -Occupational type (substituted phenolic compounds and therapeutics like monobenzyl ether of hydroquinone (Benoquien 20). The patches of depigmentation are sharply defined and in some patients may be surrounded by hyperpigmentation, some spotty perifollicular pigment may be seen within the depigmented patches and this is the first sign of repigmentation. Sensation in the depigmented patches is normal and in this differentiated from tubercloid leprosy.

What are the bad prognostics signs in vitiligo? 1-When there is leukotrachia (white hair). 2-Involvement of distal acral area. 3-Presence of active Koebner Phenomena. 4-Rapid progressive course. 5-Universal vitiligo(involvement all the skin). 6-Patient with unstable psychology. 22

Important disorders of body folds Intertrigo (A red, macerated, swelling, fissuring and pain in the skin folds such as retro-auricular area, interdigital fold,groin,axillar or any other skin fold is called Intertrigo).The common causes are:(1)Infections;(candida,dermatophyte,erythrasma). (2)Psoriasis. (3)Seborrhoeric dermatitis. (4) suppurativa. (5)Pemphigus vulgaris/vegetance.

Palmer erythema is seen in: 1- Healthy adult. 2- Pregnancy 3-Liver disease. 4- Thyrotoxicosis 5- Rheumatoid arthritis.

Bullous diseases: blisters are accumulation of fluid within or under the epidermis, they may have many causes; *immunological like pemphigus, pemphigoid, and dermatitis herpetiformis. *inherited disorders like epidermolysis bullosa.*viral infection like herpes simplex or herpes zoster.*cold or thermal injury.*and acute contact dermatitis. The appearance of a blister is determined by the level at which it forms(Fig.28).Subepidermal blisters occur between the dermis and the epidermis so their roof, are relatively thick, tense, and intact and may contain blood (as in pemphigoid). Intraepidermal blisters appear within the prickle cell layer of the epidermis, and so have thin roofs that rupture easily to leave an oozing denuded surface :(as in pemphigus vulgaris ): this tendency is even more marked with subcorneal blisters which form just at the outermost edge of the epidermis, and therefore have thinner roofs (as in impetigo-vesicular type). Table (2) shows distinguishing features of the three main immunobullous diseases:

Disease Age Site of blister General Blister in Nature of Circulating Fixed Treatment health month blister antibodies antibodies Pemphigus Middle Trunk, flexures Poor Common Superficial IgG to IgG -oral high dose age and scalp and flaccid intercellular intercellular steroid adhesine space -cytotoxic drugs protein -plasmophoresis Pemphogoid Old Legs often Good Rare Tense and IgG to IgG at basement -Steroid {slow flexural surfaces blood filled basement membrane dose} membrane region -cytotoxic drugs region Dermatitis Primary Elbows, knee, Itchy Rare Small IgG to IgA granular -gluten free diet adults. upper back and excoriated endomysium deposits in -dapson children buttocks and grouped muscle papillary dermis -sulphapyridine above 6years

23

Fig.28 shows electron Microscopical examination of dermo-epidermal junction

Pictures of the some skin diseases:

Fig.29 Acne vulgaris on the Fig 30 Fig.31 Actinic reticuloid back of a male.

Fig.32 photo allergic dermatitis Fig.33 Alopecia areata Fig.34

24

Fig.35 female androgenic alopecia Fig.36 Frictional alopecia Fig 37 scaring alopecia

.

Fig38 Chicken pox Fig.39 common warts Fig40 Erysipelas

Fig.41 impetigo Fig.42 impetigo as secondary Fig.43 boil infection in scabies

Fig.44 boil causes cellulites Fig.45 Staphylococcal Fig. 46 chronic paronychia scalded skin syndrome

Fig.47 Tinea circinata –see Fig.48.Tinea circinate-see the the multiple rings active borders Fig.49 Tinea fascie

25 Fig.50 Tinea mannum Fig.52 Tinea pedis extends to Fig.51 Tinea pedis sides of foot & leg.

Fig.54 Cutaneous leishmaniasis Fig.5 3 Tinea cruris Fig 55 Licking dermatitis

Fig 56 Atopic dermatitis Fig.57 periniosis (cold hypersensitivity) Fig 58 ichthyosis

Fig.59 spider nevus Fig 60 Cutaneous vasculitis Fig.61 multiple haemengiomas syndrome

Fig 63 Fixed drug eruption Fig. 64 chronic paronychia Fig 62 port wine nevus

Fig 67 piebaldism Fig.65 seborrhoeric keratosis Fig.66 Erythema26 annular centrifugum.

Fig.70 squamous cell carcinoma Fig.68 nodular xanthoma Fig.69 Cutaneous horn

Fig 72vitiligo

Fig 73 Kaposi sarcoma

Fig.71 basal cell carcinoma

Chiken pox 27 tuberculoid leprosy

ti

tinea corporis tinea cruris

r 28 erythema multiforma

tineaincognitorrrrr

29 tineafascei tinea

Tinea incognito

30 favus steroidcomplication

s corporis(incognito)

31 s

32 33 34 35 periniosis

c

36 molloscumcontagiosum

37

38 elu

39 40 41 42 43 44 45 46 47

48

49