Dermatology Dr. Hussein A. Al-Sultany 2015-2016

Fungal Skin Infections

Microbiology: Fungi exist in two basic forms: 1- (consist of long filaments of cells called hyphae) as , the molds grow and fragment into spores. 2- (single cell) as Candida, which is reproduced by budding. Some fungi are dimorphic (can exist as or depending on the temperature) as Pityrosporum.

Dermatophyte Infections ● , have the ability to infect and survive on keratin only (skin, hair, and nail). ● They caused by three genera: Microsporum, , and Epidermophyton. ● Dermatopyte classified according to their origin into: Anthropophilic (human source), Zoophilic (animal source), Geophilic (soil source). Zoophilic infections usually elicit a brisk inflammatory response.

Clinical presentation: Infections with dermatophytes are usually called Tinea (ringworm); for further description, the anatomical site is added, including:

1- Tinea of the trunk and limbs ( or T. circinata): It can occur at any age. The clinical infection usually starts from an inoculation site and spreads peripherally, where the lesion becomes more pronounced (active border). The active border: is a very characteristic pattern of dermatophyte infection, typically the active border is scaly, red, and slightly elevated, a few small vesicles and pustules may be seen within them. The lesions expand slowly and healing in the centre leaves a typical ring-like pattern, this characteristic annular appearance results from the immunological elimination of the fungus from the centre of the lesion, and the subsequent resolution of the inflammatory host response at that site.

2- Tinea of the groin (): This is common and affects men more often than women. The children are rarely affected. The upper inner thigh is involved and lesions expand slowly to form sharply demarcated plaques with active border. The scrotum is usually spared. DDX: intertrigo, (irritant or allergic), , erythrasma (bacterial infection), , and .

3- Tinea of the face (Tinea faciei): It is limited to the glabrous skin of the face in adult males. In pediatric and female patients, the infection may appear on any surface of the face, including the upper lip and chin. The lesions have annular shape with active border

4- Tinea of the beard (): It is a superficial dermatophyte infection that is limited to the beard areas of the face and neck and occurs almost exclusively in adult males. Like , the hairs are infected and easily removed (easily epilation).

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5- Tinea of the foot (Tinea pedis, Athlete’s foot): It is a common type of dermatophyte infection. The forth web space is most commonly involved. A warm moist environment of the of the toe webs predispose for this infection. The involved area is usually white, macerated, and soggy, with itching.

6- Tinea of the hands (Tinea manum): It appears dry diffuse and keratotic, at the palmar surface.

7- Tinea of the nails (Tinea ungium, ): The initial changes occur at the free edge of the nail, which becomes yellow and crumbly. Subungual hyperkeratosis, onycholysis, and thickening may then follow. Usually only few nails are infected but rarely all are.

8- Tinea incognito (steroid modified tinea): Fungal infections treated with topical steroids, appear as diffuse erythema and scales with scattered papules and pustules, and usually lose their characteristic features (annular shape with active border).

9- Tinea capitis: ● Tinea capitis is a of the scalp and associated hair (which lost and become easily epilated). ● It occurs mainly in children (boys more than girls),and it is very rare in adults (because fatty acids from sebaceous glands inhibit dermatophyte growth). ● Tinea capitis trasmited usually by direct contact (with infected human or infected animal) or from contaminated fomites. Transmission is higher with: decreased personal hygiene, overcrowding, and low socioeconomic status. ●The most important differential diagnosis of tinea capitis is in which the skin is smooth without any signs of inflammation or scaling. Types and clinical presentation: A- Noninflammatory Type (Gray Patch): It is the most common type in Iraq. Hairs in the affected area turn gray and lusterless and break off above the level of the scalp with minimal Inflammation. It is usually result from anthropophilic dermatophyte B- Inflammatory Type (): A sever inflammatory reaction with a boggy tumor like mass that exudes pus. It is usually result from zoophilic dermatophyte (cats, dogs and cattles). Inflammatory lesions are usually pruritic, and may be associated with pain, posterior cervical lymphadenopathy, and fever. If not treated properly; it is often results in scarring alopecia. C- “Black Dot” Tinea capitis: Hairs broken at the level of the scalp leave behind black dots in the areas of alopecia . D- (honeycomb): Characterized by thick yellow crusts (scutula), which may lead to scarring alopecia.

Dermatophytid “id” Reaction: A non infective cutaneous eruption (usually papulovesicular) representing an allergic response to a distinct focus of a dermatophyte infection. The condition disappears spontaneously when the primary infection is improved.

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Diagnosis of Dermatophyte Infections (Tinea): 1- Potassium Hydroxide (KOH): The scale is scraped on a glass slide with a surgical blade. The highest number of hyphae are located in the active border and so is the best area to obtain a sample for examination. Other samples can include nail clippings (in onychomycosis), or hair plucking (in tinea capitis). A drop or two of the KOH solution (10-20%) is added on a glass slide then examined under a microscope. Dermatophytes appear as translucent branching filaments (hyphae). In tinea capitis the spores may seen inside the hair shaft () or on its surface (ectothrix). 2- Wood’s light: It is a UV light of 365 nm, obtained by passing through a special filter (Wood‟s filter). It is used in the diagnosis of tinea capitis, giving a green flourecent color. 3- Culture: The common media used is the "Sabouraud's Dextrose Agar".

Treatment: A- Topical: This is all that is needed for limited skin infections. 1- Imidazole group (miconazole, clotrimazole, and ketoconazole) cream or lotion. Ketoconazole shampoo added to tinea capitis. 2- Terbinafine. 3- Tolnaftate. B- Systemic: 1- Griseofulvin: act against dermatophyte only. It is relatively safe, and it is the most widely used drug for children (dose: 10-20 mg /kg for 2 months in tinea capitis). 2- Imidazole group (ketoconazole): can cause hepatic toxicity. 3-Triazole group (itraconazole and fluconazole): these newer drugs are more effective and less likely to cause hepatic toxicity than ketoconazole. Itraconazole (100mg cap) used twice daily. In onychomycosis used one week each month for 2-4 months (pulse therapy). Fluconazole (150 mg cap) usually used once weekly. ● Azole groups (imidazole and triazole) are broad spectrum antifungal (act against dermatophyte, yeast, and Pityrosporum infections). 4- Terbinafine: It is fungicidal, and has produced rapid and long lasting remissions.

● Systemic antifungal should not be given for pregnant patients. ● Systemic steroids for a short period along with antifungal therapy greatly diminish the risk of scarring in sever inflammatory tinea capitis. Indication of systemic antifungal in dermatophyte infections: 1- Tinea capitis. 2- Onychomycosis. 3- Tinea incognito. 4- Widespread infection. 5- Immunocompromised patient. 6- Recurrent or persistent infection.

3 Candidiasis

Cause: .

Predisposing factors: C. albicans is an apportunistic organisim acting as a pathogen in the presence of certain prediposing factors, including: 1- Mechanical factors: local occlusion, moisture and/or maceration, dentures, occlusive dressings, and obesity. 2- Nutritional factors: iron deficiency, and malnutrition. 3- Physiologic alterations: extremes of age, and pregnancy. 4- Systemic illnesses: endocrine disease (diabetes mellitus, cushing disease), malignancy, and immunodeficiency. 5- Iatrogenic: catheters and medications (steroid, broad spectrum AB, and OCP).

Presentation: This varies with the site:

1- (Thrush): one or more whitish adherent plaques appear on the mucous membranes. If wiped off they leave an erythematous base.

2- Angular cheilitis (Perlèche): is characterized by erythema, fissuring, maceration, and soreness at the angles of the mouth.

3- Genital candidiasis: A- Vulvovaginitis: white curdy plaques adherent to the inflamed mucous membranes, and a whitish discharge. The eruption may extend to the groin folds. B- Balanitis: in males similar changes occur under the foreskin, and on the glance.

4- : Candida albicans may be the sole pathogen in chronic paronychia, or be found with other micoorganisms as Proteus or Pseudomonas. The proximal and sometimes the lateral nail folds of one or more fingers become bolstered and red and the cuticles are lost. Mostly seen in house wife (water and detergent exposure). Acute paronychia is usually bacterial (staph. aureus).

5- Candidal nail infection: generally results from candidal paronychia and starts near the nail fold. The nail plate becomes ridged and yellow.

6- Flexural candidiasis: A moist glazed area of erythema and maceration appears in a body fold; the edge shows soggy scaling, with outlying satellite papulopustules. These changes are most common in the groin, axillae, or under the breasts. Napkin candidiasis: it is a type of flexural candidiasis, occurs usually due to occlusion by wet diapers, and misuse of steroid combination compounds (as nystacort, which contain potent steroid and weak antifungal agents).

7- Erosio interdigitalis blastomycetica: Oval shaped macerated white area on the finger webs, mostly the third web between the middle and ring finger. Mostly seen in diabetic patients, or in persons with frequent water exposure of their hands. 4

8- Chronic mucocutaneous candidiasis: It is a chronic, treatment-resistant, candidal infections of the skin, nails, and mucous membranes. There are specific inherited abnormalities in cell-mediated immunity, several different forms have been described including those with autosomal recessive and dominant inheritance patterns.

9- Systemic candidiasis: This is seen against a background of severe illness, leucopenia or immunosuppression. The skin lesions are begin as erythymatous macules that may become papular, nodular, pustular, or ulcerative.

Investigations: 1- KOH examination: candida appears as oval cells (yeast), and sometimes as elongated cells (pseudohyphae). 2- Culture: Sabouraud's Dextrose Agar. 3- Investigations for the suspected predisposing factors. ● Wood's light is not useful in all types of candidal .

Treatment: General measures: Predisposing factors should be sought and eliminated. Topical: Imidazole group (miconazole, clotrimazole, and ketoconazole), amphotericin, nystatin, and gention violet, all are effective topically. Systemic: Oral itraconazole (twice daily) or fluconazole (once weekly) can be used, they are indicated for: 1- Recurrent candidiasis in immunocompromised. 2- Sever or recurrent genital infection. 3- Candidal paronychia and nail infections. 4- Chronic mucocutaneous candidiasis. 5- Systemic candidiasis.

5 Pityriasis Versicolor

It is a common fungal skin infection. The old name, , should be dropped, as the disorder is caused by commensal yeasts (Pityrosporum) and not by dermatophyte.

Cause: Pityriasis versicolor is caused by the dimorphic organism (), which is the pathogenic form of the commensal yeasts (Pityrosporum). It is a lipophilic organism (presents in highest number in areas with increased sebaceous activity). Recent researches has shown that, the genus Malassezia includes 12 species, and the majority of pityriasis versicolor is caused by Malassezia globosa, while the classical old species is .

Predisposing factors: Cushing syndrome, pregnancy, OCP, malnutrition, corticosteroid therapy, heat, and humidity; cause the Pityrosporum to convert to its pathogenic form (Malassezia).

Presentation and course: ● The disease mostly seen in adolescent and young adult (age of high sebaceous activity) and rare in children, and mostly occur in summer months. Typical sites are the upper trunk; neck, chest, upper back, & shoulders (areas with high sebaceous activity). ● It presents as asymptomatic or slightly itchy, scaly, hypopigmented (in dark skin) or hyperpigmented (in white skin) macules (so termed versicolor). The scales are accentuated by stretching. ● The infectivity of the disease is very low and can be regarded as non-infectious. ● Mechanisms of pigmentary change are unclear; darkening may result from hyperkeratosis, but lightening result from direct inhibitory effect on melanocytes by the carboxylic acids which is released by the organisms.

Investigations: 1- KOH: show a mixture of hyphae and yeasts (a „spaghetti and meatballs‟ appearance). 2- Wood's light: show yellow fluorescence.

3- Culture.

Treatment: Topical: it is indicated for limited disease, treatment options include: 1- Imidazole (miconazole, clotrimazole, and ketoconazole) cream, twice daily for 2–4 weeks. Ketoconazole shampoo for 5-10 minutes daily for 3 days. 2- Selenium sulphide suspension or shampoo for 10 minutes daily for one week. 3- Recently Iraqi researches proved that lactic acid solution and diclofenac gel are effective alterative therapies. Systemic: Indicated for extensive or resistant infection or frequent recurrences, include: Itraconazole (200 mg once daily for one week), fluconazole (400 mg single dose), or ketoconazole (400 mg single dose). Prevention: recurrence is common after any treatment, so it may be prevented by: once weekly application of ketoconazole shampoo, or once monthly oral itraconazole, fluconazole, or ketoconazole for 6 months.

"Best Regards" 6