A 16-year-old girl who just returned from a camping trip reports an intensely pruritic vesicular rash. The most likely diagnosis is
A) Rhus dermatitis
B) Lyme disease
C) Chigger bite
D) Brown recluse spider bite
E) Black widow spider bite
The answer is A. (Rhus dermatitis)
Discussion:
Poison ivy or poison oak is also referred to as Rhus dermatitis. The condition is associated with intensely pruritic linear streaks of vesicles, papules, and blisters. The plants contain a resinous oil that gives rise to an allergic response approximately 2 days after exposure. Contrary to common belief, the fluid in the blisters can neither transfer the rash to others nor cause it to spread.
Treatment involves topical steroid creams, Burow’s solution, calamine lotion, antihistamines, cool baths with colloidal oatmeal, and oral steroids (for 2 to 3 weeks to prevent rebound dermatitis) for more widespread cases.