1. Erin Pratt Board ReviewDermatology

2. Type III Hypersensitivity reaction to proteins in antiserum or antibiotics Si/sx: fever (prior to rash), malaise, arthralgias, GI issues, LAD and urticarial rash Characteristic serpiginous erythematous and purpuric eruptions on hands and feet at junction of plantar and palmar skin Serum Sickness

3. Serum Sickness

4. Common drugs we use: Cephalosporins (Ceclor, Keflex), Bactrim, Captopril, PCN, Dilantin • Treatment: • D/C offending agents • Symptomatic antihistamines, pain relievers, steroids • Resolves spontaneously Serum Sickness

5. Acariusscabiei • Highly contagious direct contact with infested human • Hypersensitivity reaction to mite • Characteristic eruption 4-6 weeks after contact pruriticpapules, vesicles, pustules and linear burrows • Linear burrow, made by female mite, is pathognomonic • Areas: finger and toe webs, axillae, flexor surfaces of wrists and elbows, around nipples and waist, and groin and buttocks • Infants and Toddlers: head, neck, trunk, palms, soles, dorsa and instep, lateral wrist (also more prone to nodular reaction) Scabies

6. Scabies

7. Scabies Diagnosis can be masked by excoriation, secondary infection or secondary eczematous eruption Consider scabies if no h/o atopic derm but severe pruritus and recent onset of eczema type rash Look to the distribution to help with diagnosis

8. Diagnosis: skin scraping with mineral oil (burrows or papules) Treatment: Elimite (Permethrin 5% cream) apply head to toe at night and wash off in am or Lindane lotion May have to repeat treatment Can use oral antipruritics or topical steroids for secondary reactions Scabies

9. Acne vulgaris disorder of pilosebaceous apparatus Areas: face, back and upper chest As early as 8 yrs but typically during puberty Androgens stimulate sebaceous gland differentiation and growth and production of sebum Exact pathogenesis is unknown Acne

10. Closed comedones (blackheads)/ Open comedones (whiteheads) Proliferation of Propionibacterium acnes in noninflammatory comedones and rupture of the contents into the dermis may lead to inflammatory papules, pustules and cysts Cystic acne frequently leads to scarring Acne

11. Treatment: • Mild to Mod: topical retinoic acid, benzoyl peroxide, and anitbiotics • Mod to Severe: oral antibiotics with topical agents • Oral 13-cis retinoic acid or isotretinoin should be reserved for severe, scarring cystic acne not responding to conservative measures above Acne

12. Poxvirus • Sharply circumscribed single or multiple skin-colored, dome-shaped papules with waxy surface. Usually umbilicated center although can have protruding white center. • Areas: trunk, axillae, face, and genitals • Contagious, spread by scratching so often in linear pattern • Curdlike core often expressed (typical molluscum bodies under microscope) • Treatment: sponateous remission; Can curette the core or use blistering agent followed by plastic tape for three days Molluscum

13. Molluscum

14. Repetitive “hair pulling” or twisting • Short broken-off hairs with different lengths in adjacent areas often in broad, linear bands • Areas: vertex or sides of scalp, eyebrows and eyelashes • Often caused by situational stress or habitual behavior in school-aged or adolescnets; also seen in psych patients • Often denied by patient and parents • Distinguished from alopecias by no areas of complete baldness and hair follicles not easily removed Trichotillomania

15. Trichotillomania

16. Trichophyton tonsurans causes 95%of scalp ringworms; Microsporum canis (dog/cat ringworm) Endemic in school-aged black children Diagnosis: KOH exam of hair pulled not cut to look at root; Wood light only floresces M. canis not T. tonsurans Several presentations: TineaCapitis

17. 1. Mild erythema and scaling of scalp with partial alopecia 2. Endothrix invades hair causing breakage in “salt-and-pepper” appearance TineaCapitis

18. 3. Annular lesion simulating tineacorporis 4. Erythema, edema and pustular formation from sensitization ruptures causing golden crusts simulating impetigo TineaCapitis

19. 5. Patches of heaped up scale in association with small pustules 6. Kerion raised, tender, boggy plaques or masses with pustules simulating an abscess TineaCapitis

20. Treatment: • Topicals do not penetrate deeply enough • Griseofulvin or ketoconazole over 2-4 months • Concurrent use of Selenium sulfide 2.5% reduces spore formation and shedding • High risk of recurrence TineaCapitis