Incidence of anaphylactic self-treatment in an outpatient population

Insect-allergic and food-allergic patients with a history of previous anaphylactic reactions were retrospectively and prospectively evaluated for incidence of self-administration of epinephrine or antihistamines. Participants were prescribed either Ana-KitR or Epi-PenR dosage forms. In 33 patients, 82 incidents were noted during 1,252 patient-months, an average of 0.78 incidents per patient-year (PPY). A mean of 0.38 epinephrine uses PPY was recorded, ranging from 0 to 2.82 doses PPY. Antihistamine uses averaged 0.69 PPY, ranging from 0 to 4.47 doses PPY. Antihistamines alone quelled reactions in 13 of 17 incidents involving Ana-Kits. Food-allergic patients were more likely to self-medicate, with 1.93 anti-allergic drug uses PPY, compared with 0.49 uses PPY for insect-allergic patients. Six of 22 insect-related epinephrine uses occurred during winter months. No statistically significant difference was noted between drug administration rates determined retrospectively and prospectively.