Cutaneous Disorders Flashcards
Tx for seborrheic dermatitis in peds AKA cradle cap
Soap and water
Emollient (petrolatum, mineral oil) or selenium sulfide shampoos
Low-potency topical corticosteroids only for extensive or persistent cases
Ketoconazole shampoo
Distinguishing diaper rashes (seborrheic dermatitis vs. candidal dermatitis vs. contact dermatitis)
Seborrheic Dermatitis
- “greasy,” transparent to pink-red patches that are macerated located on scalp, ears, face, chest, groin
Candidal dermatitis
- beefy red plaques with satellite lesions
Contact dermatitis
- Erythematous, indurated, scaly plaques (severe cases with vesiculation and bullae)
Which rare potentially life-threatening disease can present resembling a candidal diaper rash?
Langerhans cell histiocytosis
Tx for seborrheic dermatitis when involves body areas other than scalp in infants
Ketoconazole 2% cream or a low potency topical corticosteroid (hydrocortisone 1% cream)
Timing of rash in parvovirus B19 infection
URI sx for 3-4 days then “slapped cheek” rash
Most common cause of impetigo?
Staph aureus followed by group A strep
Tx for impetigo
Limited number of lesions: topical mupirocin
Numerous lesions or involvement of more than one area:: oral abx such as cephalexin or dicloxacillin
Symptoms of IgA vasculitis (Henoch-Schonlein Purpura)
- Palpable purpura - lower extremities and buttocks (NORMAL platelets)
- Colicky abdominal pain - can complicate to intussusception
- Heme-positive stool
- Microscopic hematuria, proteinuria, elevated BUN/Cr
- Arthralgias
Uncommon: orchitis or testicular torsion
Most commonly implicated medications leading to SJS or TEN
- Allopurinol
- Antiepileptic meds
- Lamotrigine
- Sulfonamide abx
- Sulfasalazine
- Oxicam NSAIDs
Classic drug reaction patterns: a series
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Which tinea infections in children always requires systemic antifungal therapy?
Tinea capitis, tinea unguium (onychomycosis)
Griseofulvin, terbinafine, fluconazole, itraconazole
What is the most common cause of death from seafood consumption in the United States?
Vibrio vulnificus septicemia
What is Dyshidrotic Eczema?
Vesicular rash typically found on the palms, soles, and sides of fingers that presents in the third decade of life with lifelong occurrences
Has similar appearance as herpes, lesions are opaque and deep-seated, either flush with the skin or slightly elevated and do not break easily
Description of erythema multiforme
Target-like lesions - central dark papule surrounded by a pale area and halo of erythema
Causes of erythema multiforme
- Herpes simplex (most common viral cause)
- Mycoplasma
- Sulfonamides
- Penicillins
- Barbiturates
- Phenytoin
- NSAIDs
- Oral hypoglycemics
- Lupus
- Hepatitis
- Lymphoma
What is the most common corneal lesion in herpes zoster ophthalmicus?
Punctate epithelial keratitis
Pseudodendrites are also associated (no terminal bulb)
Main difference between staphylococcal scalded skin syndrome vs. SJS
SSSS - circumoral erythema without mucosal involvement
SSSS toxins target desmoglein 1 which is not predominant in mucosa
What is a fixed drug eruption?
Solitary erythematous patch that is round or oval and well-circumscribed
- Typically pruritic
- May become dusky and violaceous
- Swelling, bullae, and erosion of lesion may occur
Common causes of fixed drug eruptions
- Tetracyclines
- Sulfonamides
- Fluoroquinolones
- Penicillins
- Dapsone
- NSAIDs
- Barbiturates
- Acetaminophen
- Antimalarials
Why are breastfed infants less likely to get diaper dermatitis?
The pH of their feces is lower
Risk factors for melanoma
- Ultraviolet irradiation (particularly light-skinned individuals)
- BRAF gene
- Family hx
- Dysplastic nevi
What is the most important factor in melanoma?
Depth
Characteristics of epidermal cysts (sebaceous cysts)
- skin-colored lesion
- present for long period of time
- often with central punctate area
- white or yellowish waxy material drainage
What genetic condition is associated with numerous epidermoid cysts on face, ears, trunk?
Gardner syndrome
What is a pilar cyst?
Firm, slow-growing nodule similar to epidermoid cyst, but grow from root of hair follicle, so more often located on the scalp
What key clinical findings differentiates erysipelas from cellulitis?
Sharp demarcation from uninvolved skin
Can also spread to pinna of ear, whereas cellulitis cannot
Tends to have acute onset with systemic manifestations whereas cellulitis is more indolent
Erysipelas involves upper dermis and superficial lymphatics
Cellulitis involves deeper dermis and subcutaneous fat
Common cause of erysipelas
Beta-hemolytic streptococci
Classic manifestation of erysipelas
Butterfly pattern over face
Tx for erysipelas
Mild-moderate: Amoxicillin, cephalexin
Systemic: Ceftriaxone or cefazolin
Description of erythema multiforme
Sudden appearance of erythematous violaceous macules and papules
Commonly found on soles of feet and palms of hands
Lesions are target-like with a central dark papule surrounded by a pale area and a “halo” of erythema
Causes of Erythema Multiforme
- HSV (most common viral cause)
- Mycoplasma
- Drugs: SOAPS - sulfa, oral hypoglycemics, anticonvulsants, penicillin, nSAIDs
- Lupus
- Hepatitis
- Lymphoma
Tx of Erythema Multiforme
Mild: supportive - oral antihistamines and topical steroids
Severe (significant mucous membrane involvement): systemic corticosteroids
Pathophysiology of Kerion
Starts as tinea capitis (painless) that then undergoes delayed-type hypersensitivity reaction to causative fungus which causes initial erythematous, scaly plaque to become boggy with inflamed purulent nodules and plaques and the hair follicle is destroyed by the inflammatory process leading to scarring alopecia
Clinical presentation of Kerion
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- Painful
- Hair loss
- Fever
- Lymphadenopathy
Tx for kerion
Oral griseofulvin
Abx to treat any secondary bacterial infection
Oral corticosteroids to treat severe inflammation
What is black dot Tinea capitis?
Refers to an infection that causes the individual hairs to fracture, leaving the infected dark stubs visible in the infected regions
Locations commonly involved in stasis dermatitis
Medial distal and pretibial area of the legs; bilateral malleoli
What are the EFG prediction criteria added to the ABCD prediction rule for diagnosing unpigmented nodular melanomas?
Elevation
Firm on palpation
Continuous growth for 1 month
Characteristics of basal cell carcinoma
- Pearly nodule
- Telangiectatic vessels
- “Rolled” raised edge
Characteristics of squamous cell carcinoma
- Indurated and ulcerated papule
- May bleed
- Arise from actinic keratosis
What are five treatments for genital warts caused by HPV?
- Podofilox
- Imiquimod
- Cryotherapy
- Trichloroacetic acid
- Surgical removal
What is the most common STD?
HPV
Risk factors for MRSA
- Recent hospitalization/surgery
- Hemodialysis
- HIV infection
- IVDU
- Purulence
- Residence in long-term healthcare facility
Abx regimens to cover cellulitis with MRSA coverage
- Amoxicillin and minocycline
- Amoxicillin and doxycycline
- Bactrim
- Clindamycin
What risk factor has the strongest association for cellulitis
Lymphedema
Pahtophysiology of pemphigus vulgaris
IgG autoantibodies against keratinocytes and their desmosomes
Tx for pemphigus vulgaris
Steroids and immunomodulators such as azathioprine, cyclosporine, or methotrexate
Dispo for pemphigus vulgaris
Admission - high mortality
Mechanism of pemphigus vulgaris
Bullae and blister formation from deposition of immunoglobulin G autoantibodies in the epithelial cell surface
IgG against keratinocytes in desmosomes causing acantholysis
