Your fellow resident just returned from a long lunch break, raving about how good his meal was. He doesn’t seem to notice, but his breathing is labored and his face and arms are covered in an urticarial rash.
What is the most likely condition?
- mild allergic reaction
- scombroid poisoning
- malingering; he’s avoiding going back to work
Answer: B; Scombroid is due to improperly prepared fish causing a histamine reaction; the chicken pad thai did not contain fish. The anaphylactic reaction was likely due to peanuts.
Anaphylaxis is an allergic reaction most commonly defined as the involvement of skin (urticaria, itching) AND one of the following organs:
- Respiratory (wheezing, stridor, SOB)
- Cardiovascular (hemodynamic instability)
- GI (abd pain, n/v)
-Epi (1:1000) 0.3mg IM. May repeat doses
-H1 blockade: diphenhydramine (Benadryl) 50mg IV
-H2 blockade: ranitidine, famotidine
-Steroids: Solu-medrol, up to 125mg IV
-Consider Glucagon 1mg if on home beta-blockers, which may inhibit the effects of epi
-Epi drip 2-10 mcg/min if severe reaction with hemodynamic compromise.
What if the epi drip is not readily available?
Take epi 1 mg (1 amp in crash cart) and inject into 1L of NS.
This equals 1000 mcg epi in 1000mL NS.
This equals 1 mcg/mL epi.
(See http://www.aliem.com/dirtyepi/ for further details)
- Simons FER. Anaphylaxis: Rapid recognition and treatment. Uptodate