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
Vitiligo
1. Appearance
2. Treatment
- White macules and patches (DEpigmentation), margins can be hyperpigmented
- Potent topical steroid, UVB if more extensive, sun protection
Most people will at least check thyroid function
Accutane side effects and screening
Dry lips, skin, mouth, sun sensitivity, back and joint pain
Hypertriglyceridemia, increased LFTs - get triglyc, chol, and LFTs before starting, then 4 and 8 weeks after
Erisipelas
Bright pink, well demarcated plaques
Superificial infection from spread through dermal lymphatics
Better defined borders and develops faster than cellulitis
Treat with antibiotics
Natural history and timeline of infantile hemangiomas
Not present at birth
Show up in first 1-2 weeks of life, no later than 3 mo
Proliferative phase for first 6 mo
Plateau 6-12 mo
Involute around 1 year old
Which hemagiomas need further work up?
5+ cutaneous - abdo US for liver hemangiomas
Segmental beard area - risk of airway
Large segmental facial lesions - ?PHACES
Lumbosacral/perineal segmental lesions - ?LUMBAR syndrome
Congenital hemangiomas
Present at birth
May or may not involute
Cannot treat with beta blockers
Pityriasis rosacea rash and treatment
Adolescents, trunk, may have viral prodrome (HHV 6 or 7)
Often first presents with Herald patch (annular, central clearing)
Well demarcated generalized erythematous plaques/papules with collarette of scale
Resolves by 3 mo, can treat itch
Nail changes in psoriasis
Oil drop sign
Pitting
Nail fragility
Onycholysis
Treatment for
1. Mild to moderate
2. Moderate to severe
psoriasis
- Topical steroids, CIs, vit D analogues, emollients
- TNF inhibitors, phototherapy, MTX
Yearly screening for patients with psoriasis
Weight check
BP
Mood
Arthritis
Uveitis (if psoriatic arthritis)
Acne classification
Mild = mainly comedones, < 10 papules/pustules
Moderate = 10-40 papules/pustules, may have back/trunk lesions
Moderate-severe = 40-100 papules/pustules, up to 5 nodules, widespread affected areas
Severe = nodulocystic, multiple large painful nodules
Treatment for mild comedonal acne
Topical retinoid
Alt. topical salicyclate or azelaic acid
Treatment for mixed papular/pustular acne
Topical retinoid
+/- BPO, topical antibiotic (erythromycin, clindamycin)
Use topical abx with BPO to prevent resistance
Can use combo products
When to add PO abx for acne
Moderate to severe inflammatory papulopustular and nodulocystic acne
Anti-inflammatory and antibacterial properties
Use with topical retinoids and BPO, not topical abx
Ex: minocycline, doxycycline > tetracycline
When to use OCP for acne
Acne and hormonal abnormalities
Acne unresponsive to antibiotic therapy, not candidates for isotretinoin
Alopecia areata
Sudden, oval, well demarcated patches of COMPLETE alopecia
No rashes or scarring
Surrounding exclamation point hairs
Tx: potent topical steroids, injection steroids, cosmetic coverings
Erythema toxicum
Lesions are firm, yellow white, 1-2 mm papules or pustules with surrounding erythematous flare
Peak incidence on second day of life – waxes and wanes over first few days (lasts 3-7 days)
Neonatal pustular melanosis
Transient, benign, self limiting condition
3 types of lesions: evanescent superficial pustules, ruptured pustules with fine scale +/- central hyperpigmented macule, and hyperpigmented macules
Present at birth!
Pustules last 2-3 days, hyperpigmented macules can last up to 3 months
Miliaria
Results from retention of sweat occluded in eccrine sweat ducts
Asymptomatic, noninflammatory, pinpoint, clear vesicles
From overheating
What age group always needs a work up if presenting with acne?
Mid-childhood acne (ages 1-7 years)
Consider precocious puberty, late onset CAH, or androgen secreting tumors
Sucking blister
Solitary or scattered superficial bullae
Present at birth on upper limbs
Presumably induced by vigorous sucking in uteror
Radial aspect of forearm, thumb, and index finger
Resolves without treatment
May see sucking pads (calluses) on the lips
Tinea capitis
1. Rash presentation
2. Diagnosis
3. Treatment
- Partial alopecia with scale, often occipital lymphadenopathy
- Fluoresce under Wood’s lamp, take fungal scraping for KOH and culture before treatment
- SYSTEMIC antifungals! Oral terbinafine x 4-6 weeks, also griseofulvin for 6-8 weeks, treat with antifungal shampoo to reduce risk of spread of infection to other household members, systemic steroids if kerion present
Scabies treatment
5% permethrin 8-14 hours, repeat 7 days later
Infants: scalp and face to toes
Children: neck to toes
Prophylactic therapy for household members regardless of symptoms
