Derm 1 Flashcards
(34 cards)
Atopic dermatitis pathogenesis
type 1 IgE mediated hypersensitivity rxn → mast cells release histamine creating itching and basophils in dermis
Pt with Atopic dermatitis may also have experienced what other conditions?
asthma or allergic rhinitis
What are the signs and symptoms of Atopic dermatitis?
Where does it usually present?
- “itch that rashes”
- BI-LATERAL symmetrical papules or plaques, edema, erosion w/ or w/o scales or crusting on ★ flexor surfaces ★ , neck, eyelids , face, dorms of hands and feet
What are the clinical features of atopic dermatitis
non infectious
- pruritic (persistent xerosis)
- flexural linchenification (not well demarcated)
- facial and extensor surfaces in infancy
- personal or family hx of allergic rhinitis or asthma
- Dennie-morgan lines **
- Hyperlinear palmar creases
What are itching triggers of atopic dermatitis
mites, foods, EtOH, cold/hot/humid, weather
What is the histology of atopic dermatitis
- hyperkeratosis (piling up of skin cells)
- acanthosis (epidural thickening)
- excoriation (scraped skin)
- staph colonization may be noted
- eosinophil deposition
How often does Infantile atopic dermatitis occur ?
60% of cases present in 1st year of life usually after 2 months (when mothers natural antibodies of weened off)
Where does infantile atopic dermatitis occur and what does the lesions look like?
- cheeks, chest, neck, extensor/flexor extremities
- lesions→ scaly, red occasionally oozing plaques (symmetric)
What can occur after a result of a flare up of atopic dermatitis? What what you see on different skin tones?
post inflammatory hyper/hypo pigmented changes
darker skin: hyper/hypo
lighter skin: hyper
What are three differential diagnosis for atopic dermatitis ?
- contact dermatitis (not location and potential exposure)
- scabies (note distribution and hx)
- psoriasis (not location usually extensor surface than flexor , FH, less pruritic)
)What are the many forms of treatment for atopic dermatitis ?
-topical steroids
→ mainstay treatment (applied for short periods of time and stopped when healed)
-Antihistamines
→ hydroxyzine (sedating)
→ Cetrizine (less sedating)
-Topical Immunomodulators
→ Protopic/Elidel (Tacrolimus and Pimecrolimus) (non steroidal cytokineinhibitor); used as an addition/alternative to topical steroids; good for long term use
-Non steroidal
→ Crisaborle (phospodieterase 4 inhibitor)
-Biologic
→ Dupilumab( binds and inhibits IL-4; SC injection q 2 weeks)
-P.O. antibiotics
→ keflex 500mg qid x 10d (if evidence of secondary bacterial staph infection
Cream, ointment, foam, or gel for atopic dermatitis ?
- cream→ moisturzer (use on face)
- ointment → opaque (vaseline); occlusive
- gel→ drying (no greasy)
- lotion/foam→ great for scalp/hairy areas
What are the side effects for topical steroids?
-skin atrophy/ telangiectasis/tachyphylaxis (tolerance)
→ increase with potency
What are the signs and symptoms of Nummular Eczema?
COIN SHAPED pruritic patches and plaques, often occur in clusters, often seen in Atopic patients
What is the distribution of nummular eczema lesions?
What occurs when the lesions heal?
- Lesions occur mainly on legs may be clear centrally (resembling tine corpis)
- post inflammatory hyper-pigmentation
How do you diagnosize Nummular Eczema?
What are the differential diagnosis for N.E?
-clinical appearance and negative result of KOH
→ Tinea corporis: usually clear in the center
→ +KOH or fungal culture
How do you treat nummular eczema acutely and long term?
acute: intermediate strength topical steroid (triamcinolone cream 0.1%) or severe (clobetasol ointment) +/- occlusion
long term: treatment with less potent topical steroids
What are the signs and symptoms of Dyshydrosis?
-small vesicles appear on hands and feet associated with pruritus
→ like throwing hot dog on the grill and it bubbles up until the skin cracks
What is the treatment for Dyshydrosis?
- mild cleansers (cetaphil)
- emollient barriers creams, protective gloves
- burrows solution (antibacterial astringent)→ powder poured in water, then let it sit on skin to dry out weepy areas
- topical steroids are the mainstay
- Protopic and elidel for long term management
What is contact dermatitis ?
Examples of irritant contact dermatitis and allergic contact dermatitis ?
Term applied to acute or chronic inflammatory rxns to substances that come in contact w/ skin
Type IV delayed hypersensitivity Rxn’s
ICD: diaper rash, alkalis, acids, soaps, detergents
ACD: poison ivy & nickel
Signs and symptoms of ACD?
what is a differentia DX of ACD?
- well demarcated linear pruritic (sometimes burning) rash at site of contact (unilateral)
- poison ivy has a classic linear streaks of juicy papules and vesicles
Differential Dx:
- Herpes zoster → usually painful and unilateral following dermatome
- shingles
Treatment of Allergic Contact Dermatitis
- remove offending agen
- cool showers
- burrows solution
- potent or super potent topical steroids
- severe cases may warrant systemic steroids
Signs and symptoms?
Diagnosis is based on?
How to manage?
….Irritant Contact Dermatitis
Signs and symptoms?
→ erythematous scaly, eczematous eruption not caused by allergens
Diagnosis is based on?
→ based on history and r/p allergic dermatitis
How to manage?
→ avoid offending agent of minimize contact
Signs and symptoms of diaper dermatitis ?
How do the lesions distribute?
How do you treat it?
- eyrthema, scale papules and plaques → if neglected may erode and ulcerate
- Distribution→ lesions spares the creases ( ex: butt crack, thigh folds)
- Treatment→ zinc oxide and frequent diaper changes OTC hydrocortisone
- *if beefy red c. albican is suspected→ topical anti fungal (ketoconazole w/ nystatin powder )
