Transcript Board Review Dermatology

Erin Pratt
BOARD REVIEW
DERMATOLOGY
SERUM SICKNESS
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
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SERUM SICKNESS
SERUM SICKNESS
Common drugs we use: Cephalosporins (Ceclor,
Keflex), Bactrim, Captopril, PCN, Dilantin
 Treatment:
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 D/C
offending agents
 Symptomatic antihistamines, pain relievers,
steroids
 Resolves spontaneously
SCABIES
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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)
SCABIES
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
SCABIES
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
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ACNE
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
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ACNE
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
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ACNE
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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
MOLLUSCUM
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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
TRICHOTILLOMANIA
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
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TRICHOTILLOMANIA
TINEA CAPITIS
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:
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TINEA CAPITIS
1. MILD ERYTHEMA AND SCALING OF
SCALP WITH PARTIAL ALOPECIA
2. ENDOTHRIX INVADES HAIR CAUSING
BREAKAGE IN “SALT-AND-PEPPER”
APPEARANCE
TINEA CAPITIS
3. ANNULAR LESION SIMULATING
TINEA CORPORIS
4. ERYTHEMA, EDEMA AND PUSTULAR
FORMATION FROM SENSITIZATION
RUPTURES CAUSING GOLDEN CRUSTS
SIMULATING IMPETIGO
TINEA CAPITIS
5. PATCHES OF HEAPED UP SCALE IN
ASSOCIATION WITH SMALL PUSTULES
6. KERION RAISED, TENDER, BOGGY
PLAQUES OR MASSES WITH PUSTULES
SIMULATING AN ABSCESS
TINEA CAPITIS
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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