Dermatitis and Eczema Flashcards
contact dermatitis
acute or chronic inflammatory reaction to substance that comes in contact with the skin
irritant contact dermatitis (ICD)
chemical irritant, can occur in anyone, confined to areas of exposure, certain threshold above which dermatitis occurs and below which it does not
allergic contact dermatitis (ACD)
type IV hypersensitivity reaction to an allergen, spreading reaction, occurs only in sensitized individuals
symptoms of acute ICD
burning, stinging, smarting (immediate - acid, chloroform, methanol), can start 1 -2 min, peak at 10 and fade after 30 min (delayed - propylene glycol)
presentation of acute ICD
well-demarcated erythema - vesicles and blisters - crusting - erosions, necrosis. NO papules.
symptoms of chronic ICD
stinging, smarting, burning AND itching - pain later
presentation of chronic ICD
dryness, chapping, erythema - hyperkeratosis and fissuring - lichenification, ill defined borders, crusting
treatment for acute ICD
remove offending agent, wet dressings with Burow’s solution q 2-3 h, topical glucocorticoids; 60mg red for 2 weeks with 10 mg taper
treatment for chronic ICD
remove offending agent, betamthasone or clobetasol; topical calcineurin inhibitors not enough to suppress inflammation
phytodermatitis - common offending agents
poison ivy, poison oak - oleoresins called uroshiol
derm path: ACD
spongiosis, lymphocytes and eosinophils, chronic - lichenification
Atopic dermatitis presentation
pruritus and itching leading to more inflammation and pruritus, lichenification: “itch scratch cycle”
AD microbial agents
Staph areus exotoxins, S. pyogenes
Skin barrier disruption of AD
defect in filaggrin, decreased ceramides
other atopies associated with AD
allergic rhinitis, asthma
pathophysiology of AD
type 1 HS reaction mediated by IgE as a result of vasoactive substances released by mast cells and basophils
what type of AD is common in black people?
follicular lichenification
pathogenesis of lichen simplex chronicus (LSC)
hyper excitability of lichenified skin in response to minimal external stimuli
symptoms LSC
pruritus in paroxysms
clinical presentation LSC
solid lichenified plaque with confluence of small papules. exoriations. dull red and later brown or black hyperpigmentation
path LSC
hyperplasia of all epidermal components: hyperkeratosis, acanthosis, elongated and board rate ridges. chronic inflammatory infiltrate in the dermis
mgmt LSC
occlusive bandages at night, topical glucocorticoid prep or tar prep covered by occlusive dressings for legs/arms, Unna boot: gauze roll dressing impregenated with zinc oxide paste wrapped around a large lichenified calf - left for one wee.
Prurigo nodularis
associated with AD but occurs without it; starts with piercing pruritus leading to picking and scratching. Multiple, firm, dome shaped nodules with excoriations
Tx prurigo nodularis
IL triamcinolone with occlusive dressings; neuron tin 300mg may be helpful
