Dermatology Flashcards
Mastocytosis
Caused by abnormal proliferation of mast cells
Urticaria pigmentosa is the mot common form
Typically before 1 year of age
Appearance: Orangish-brown macules, plaques, or nodules, usually on trunk, form a wheal with stroking (Darier sign)
Self resolves
Mastocytosis treatment
Avoid triggers (heat, touching, NSAIDs, ASA, opioids)
H1 antihistamines
Topical steroids for urtication or blistering
EpiPen if risk of anaphylaxis
Cromolyn sodium or ketotifen (mast cell stabilizing agent) for GI symptoms or some systemic symptoms like headache
4 modes of pathogenesis for acne
Alteration in the keratinization process
Sebum production by the sebaceous gland
P. acnes follicular colonization
Release of inflammatory mediators in to the skin
Common SJS/TEN triggers
Drugs (sulfonamides, anti-seizure medications, NSAIDs)
Infections (HSV, EBV, mycoplasma, HBV)
SJS vs TEN
< 10% of epidermis involved = SJS, typically painless or minimal
> 30% involvement = TEN, typically painful
SSSS vs SJS/TEN
Split in the skin is much more superficial (subcorneal) in SSSS compared to TEN (full-thickness)
No perioral crusting in SJS/TEN
Dermatitis herpetiformis
IgA antibodies are directed at epidermal transglutaminase
All patients with dermatitis herpetiformis have celiac disease!
Symmetric, grouped, small, tense, red, stinging, ++ itchy papules and vesicles, pleomorphic
Mucous membranes usually spared, can see on knees, elbows, shoulders, buttocks, head
Respond within weeks to months of a gluten free diet
Can cautiously give dapsone for itching
Drugs that cause photosensitivity
Antibiotics (sulfonamides, tetracyclines, fluroquinolones)
NSAIDs
Retinoids
Thiazides
Antifungals
How does BPO work
Decreases antibacterial resistance in p. acne
Birth control for accutane
2 effective BC for 1 month before, during, and 1 month after use
2 neg preg tests before starting, monthly tests during preg
What is the neuro concern for a child with giant cell pigmented nevus?
Leptomeningeal melanocytosis
Can cause seizures, hydrocephalus, increased ICP, ID, and motor deficits
Appearance of
1. Junctional
2. Compound
3. Dermal
cutaneous nevi
- Brown, flat, junction of dermis and epidermis
- Tan to brown, minimal/moderate elevation, within dermis or dermal-epidermal junction
- Pink, elevated, dome shaped, within dermis
New ABCDE for pediatric melanoma
A: Amelanotic
B: Bleeding/bumps
C: Colour uniform
D: Diameter small/de novo
E: Evolution
Tinea versicolour
1. Appearance
2. Diagnosis
3. Treatment
- Trunk, neck, arms. Reddish brown in white people, hypo or hyperpigmented in darker skin, fine scale, little to no itch
- Fungal infection, yellow under Wood’s lamp
- Antifungal shampoo or cream, can try PO
Pityriasis alba
1. Appearance
2. Treatment
- Hypopigmented, ill defined, round or oval patches with fine scale, more noticeable in the sun
- Moisturizer, avoid sun, low potency steroid or CI if itchy, red, or scaly