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SKINTEST Skin Test Christina P. Linton

1. Which fungal strain is the most common cause 6. Which of the following conditions is characterized of tinea capitis in the United Kingdom and by intraepidermal blistering? North America? a. Bullous pemphigoid a. Trichophyton tonsurans b. Porphyria cutanea tarda b. Microsporum audouinii c. Herpesvirus infection c. Trichophyton rubrum d. Dermatitis herpetiformis d. Microsporum canis 7. What is the mechanism of action of injectable local 2. What percentage of cells in the epidermis are anesthetics? keratinocytes? a. Blockage of potassium channels a. 50% b. Inhibition of cyclooxygenase b. 65% c. Blockage of sodium channels c. 80% d. Inhibition of prostaglandins d. 95% 8. Which of the following statements most accurately 3. Which of the following conditions is inherited in describes pemphigus vulgaris? X-linked fashion? a. Onset is most common in the third and fourth a. Tuberous sclerosis decades of life. b. Incontinenta pigmenti b. Initial lesions generally occur on the trunk. c. Ataxia telangiectasia c. Auspitz sign is usually positive. d. Neurofibromatosis d. Untreated disease is commonly fatal.

4. What does the Greek root of the term ‘‘ichthyosis’’ 9. What does the term ‘‘acantholysis’’ refer to on a mean? dermatopathology report? a. Fish a. Loss of intercellular connections b. Crocodile b. Reduced thickness of the granular layer c. Elephant c. Abnormal retention of keratinocyte nuclei d. Lizard d. Intercellular edema

5. Lichen striatus most commonly occurs in which 10. Approximately what percentage of untreated anatomic location? syphilis cases progressed to tertiary syphilis? a. Face a. 15% b. Chest b. 33% c. Abdomen c. 66% d. Extremities d. 85%

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ANSWERS in the early teenage years. Cutaneous manifestations include telangiectasias, caf2 au lait patches, hypo- pigmented macules, seborrheic dermatitis, prema- 1. a. Trichophyton tonsurans. In the United Kingdom ture graying, and sparsity of the hair and progeroid and North America, Trichophyton tonsurans accounts features. Neurofibromatosis is an autosomal- for more than 90% of tinea capitis cases. Occasion- dominantly inherited syndrome manifested by de- ally, cases of tinea capitis are related to pet exposure, velopmental changes in the nervous system, bones, in which case Microsporum canis is generally the and skin. Cutaneous manifestations of neurofibro- responsible fungal strain. Tinea capitis may also be matosis include caf2 au lait macules, neurofibromas, caused by any other pathogenic dermatophytes, and freckling in the axillary or inguinal regions. except for Epidermophyton floccosum and Tricho- phyton concentricum. James, W. D., Berger, T. G., & Elston, D. M. (2011). Andrews’ diseases of the skin: Clinical dermatology (11th ed.). Philadelphia, PA: Saunders/Elsevier. James,W.D.,Berger,T.G.,&Elston,D.M.(2011).Andrews’ diseases of the skin: Clinical dermatology (11th ed.). Philadelphia, PA: Saunders/Elsevier. 4. a. Fish. The term ‘‘ichthyosis’’ is derived from the Kao, G. F. (2014). Tine capitis. Retrieved from http://emedicine.medscape.com/ Greek root ‘‘ichythys,’’ which means fish. The most article/1091351-overview#a6 common form of ichthyosis is ichthyosis vulgaris, 2. c. 80%. At least 80% of cells in the epidermis are which is also called ‘‘fish scale disease’’ or ‘‘fish skin ectodermally derived keratinocytes. Keratinocytes disease.’’ Clinically, ichthyosis vulgaris is character- synthesize keratin, a long, threadlike protein with a ized by excessively dry, scaly skin. protective role. The term keratinization refers to the New Zealand Dermatological Society Incorporated. (2015). Ichthyosis vulgaris. differentiation process that occurs as the cells mi- Retrieved from http://www.dermnetnz.org/scaly/ichthyosis-vulgaris.html grate from the basal layer to the surface of the skin. 5. d. Extremities. Lichen striatus is a fairly common, During this process, the keratinocytes first pass self-limited eruption that is seen primarily in children. through a synthetic and then a degradative phase. Involvement of an extremity is most common, al- The epidermis commonly is divided into four layers though lesions can occasionally occur on the trunk, according to keratinocyte morphology and position head, or neck. Lesions begin as 1- to 3-mm papules as they differentiate and rise to the surface. The cells that are erythematous and slightly scaly. These papules begin in the basal cell layer (stratum germinativum), coalesce to form a 1- to 3-cm-wide continuous or then rise to the squamous cell layer (stratum spi- interrupted band that, over a few weeks, progresses nosum), then the granular cell layer (stratum gran- down the extremity following the lines of Blaschko. ulosum), and finally, the cornified or horny cell layer The lesions are usually asymptomatic and last for an (stratum corneum) before being shed into the envi- average of 1 year before spontaneously resolving. ronment. In addition to keratinocytes, the epidermis harbors a number of other cell populations, such as James, W. D., Berger, T. G., & Elston, D. M. (2011). Andrews’ diseases of the skin: Clinical dermatology (11th ed.). Philadelphia, PA: Saunders/Elsevier. melanocytes, Langerhans cells, and Merkel cells. 6. c. Herpesvirus infection. Herpesvirus infections Kolarsick, P.A. J., Kolarsick, M. A., & Goodwin, C. (2011). Anatomy and physiology of the skin. Journal of the Dermatology Nurses’ Association, are characterized by blistering in the spinous layer of 3(4), 203Y213. the epidermis. The other three conditions listed are Y 3. b. Incontinenta pigmenti. Incontinenta pigmenti is characterized by blistering at the dermal epidermal an X-linked dominant condition that appears in junction. More specifically, bullous pemphigoid blis- girls during the first weeks after birth. In most ters at the lamina lucida, whereas porphyria cutanea cases, vesicular and verrucous lesions occur before tarda and dermatitis herpetiformis blister below the the onset of spattered pigmentation on the trunk. basal lamina. The pigmentation occurs in the form of macules Goldsmith, L. A., Katz, S. I., Gilchrest, B. A., Paller, A. S., Leffell, D. J., & arranged in streaks, sprays, splatters, and whorls Wolff, K. (2012). Fitzpatrick’s dermatology in general medicine (8th ed.). New York, NY: McGraw-Hill Medical. that follow the lines of Blaschko. Tuberous sclerosis is an autosomal-dominantly inherited condition in 7. c. Blockage of sodium channels. Local anesthetics which affected individuals may experience adenoma exert their influence on nerves by blocking the so- sebaceum, mental deficiency, and epilepsy. Cutaneous dium channels on nerve axons. This blockage in- manifestations include periungual fibromas, shagreen hibits depolarization and the formation of an action plaques, oral papillomatosis, ash-leaf hypomelanotic potential. Because local anesthetics affect the smaller macules, skin fibromas, and caf2 au lait spots. Ataxia unmyelinated C-type nerve fibers more rapidly and telangiectasia is a rare autosomal recessive disorder in effectively than myelinated A-type nerve fibers, which affected individuals experience neurologic adequate anesthesia can be achieved while motor decline that usually results in wheelchair dependency function and pressure sensation are maintained.

84 Journal of the Dermatology Nurses’ Association

Goldsmith, L. A., Katz, S. I., Gilchrest, B. A., Paller, A. S., Leffell, D. J., & James,W.D.,Berger,T.G.,&Elston,D.M.(2011).Andrews’ diseases of the Wolff, K. (2012). Fitzpatrick’s dermatology in general medicine (8th ed.). skin: Clinical dermatology (11th ed.). Philadelphia, PA: Saunders/Elsevier. New York, NY: McGraw-Hill Medical. Roenigk, R. K., Ratz, J. L., & Roenigk, H. H. (2007). Roenigk’s 9. a. Loss of intercellular connections. Acantholysis is dermatologic surgery: Current techniques in procedural dermatology the loss of cohesion between keratinocytes because (3rd ed.). New York, NY: Informa Health Care. of dissolution of intercellular connections, sometimes 8. d. Untreated disease is commonly fatal. Pemphigus resulting in an intraepidermal vesicle. Acanthocyte is vulgaris (PV) is a chronic blistering dermatosis that an old name for keratinocyte and means ‘‘prickle cell,’’ generally occurs in the fifth and sixth decades of life. referring to the desmosomal spines that normally The lesions of PV usually first appear in the mouth connect the cells. Acantholysis differs from the (60%) or at the site of a burn or other skin injury. intercellular edema of spongiosis in that acantholytic Other common sites include the groin, scalp, face, keratinocytes tend to be rounded rather than elon- neck, axillae, and genitals. PV occurs because of an gated, the desmosomal spines appear destroyed rather autoimmune reaction, which triggers the formation than stretched, and exocytosis of lymphocytes into the of mucosal erosions and thin-walled, relatively epidermis is usually absent. Conditions in which acan- flaccid, easily ruptured bullae that appear on ap- tholysis is present include Darier’s disease, HaileyY parently normal skin and mucous membranes or on Hailey disease, all varieties of pemphigus, Grover’s erythematous bases. The fluid in the bullae is clear at disease, herpes virus infections, staphylococcal scalded first but may become hemorrhagic or even seropu- skin syndrome, and warty dyskeratoma.

rulent. The bullae rupture to form erosions, and the Bolognia, J. L., Jorizzo, J. L., & Schaffer, J. V. (2012). Dermatology (3rd ed.). denuded areas soon become partially or totally cov- St. Louis, MO: Elsevier/Mosby. ered with crusts that have little or no tendency to Rapini, R. P. (2012). Practical dermatopathology (2nd ed.). Philadelphia, PA: heal. Nikolsky sign is present (twisting or rubbing Elsevier Saunders. causes intact epidermis to shear away from the un- 10.b.33%.About 33% of untreated syphilis cases derlying dermis leaving a moist surface) as is Asboe- progress to tertiary (late) syphilis. Another 33% of Hansen sign (gentle pressure on an intact bullae untreated cases are arrested by the host, and the se- forces the fluid to spread under the adjacent skin). rum rapid plasma reagin (RPR) becomes negative. Auspitz sign refers to the appearance of pinpoint areas In the final third of untreated cases, the serum RPR of bleeding when scale is removed from psoriatic remains positive, but the disease does not progress plaques and is not associated with PV. Management during the patient’s lifetime. The symptoms of ter- of PV involves symptomatic treatment of the wounds tiary syphilis can occur months or years after infection with topical agents as well as the use of systemic im- and result from the Treponema pallidum microor- munosuppressive medications such as prednisone, ganisms invading the central nervous system, cardio- mycophenolate mofetil, or azathioprine. Prompt vascular system, skin, and other organs. Damage diagnosis and treatment leads to a more favorable then occurs because of host delayed-hypersensitivity prognosis, and untreated disease is commonly fatal. responses, which produce local inflammation and However, in treated patients, the most common gummas (locally destructive lesions) in affected cause of death is medication side effects. Treatment tissues.

is continued until clinical disease is suppressed and Bolognia, J. L., Jorizzo, J. L., & Schaffer, J. V. (2012). Dermatology (3rd ed.). pemphigus antibodies disappear from the serum. St. Louis, MO: Elsevier/Mosby.

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