Erin Pratt

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

Common drugs we use: Cephalosporins (Ceclor, Keflex), Bactrim, Captopril, PCN, Dilantin

Treatment: D/C offending agents Symptomatic antihistamines, pain

relievers, steroids Resolves spontaneously

Acarius scabiei Highly contagious direct contact with infested

human Hypersensitivity reaction to mite Characteristic eruption 4-6 weeks after contact

pruritic papules, 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)

•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

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

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

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

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

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

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

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:

1. MILD ERYTHEMA AND SCALING OF SCALP WITH PARTIAL ALOPECIA

2. ENDOTHRIX INVADES HAIR CAUSING BREAKAGE IN “SALT-AND-PEPPER” APPEARANCE

3. ANNULAR LESION SIMULATING TINEA CORPORIS

4. ERYTHEMA, EDEMA AND PUSTULAR FORMATION FROM SENSITIZATION RUPTURES CAUSING GOLDEN CRUSTS SIMULATING IMPETIGO

5. PATCHES OF HEAPED UP SCALE IN ASSOCIATION WITH SMALL PUSTULES

6. KERION RAISED, TENDER, BOGGY PLAQUES OR MASSES WITH PUSTULES SIMULATING AN ABSCESS

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