Epinephrine auto-injector prescriptions as a reflection of the pattern of anaphylaxis in an Asian population

This study surveyed the prescription patterns of adrenaline auto-injectors (AAs) in Singapore to examine the frequency, triggers, and demographic pattern of anaphylaxis requiring such prescriptions. A 6-year retrospective review of 417 consecutive patients prescribed AAs in Singapore from January 1999 to December 2004, as identified from hospital pharmacy records. There were 417 patients identified, consisting of 295 (70.7%) Singaporeans with the remaining being non-Singaporean residents. Based on population census, the frequency of AA prescriptions was estimated at 1 per 10,000 Singaporeans. Demographic factors associated with AA prescriptions were male gender (OR = 1.361; p = 0.002); minority ethnic groups, which included Eurasians, Caucasians, Koreans, and Japanese (OR = 15.873; p < 0.001); and children <15 years of age (OR = 2.593; p < 0.001). The most common food allergens resulting in AA prescriptions were peanut (41.9%) and shellfish allergy (28.5%). Multiple logistic regression analysis showed that peanut allergy was independently associated with Eurasian ethnicity (OR = 5.045; p = 0.021); and shellfish allergy with Indian ethnicity (OR = 2.757; p = 0.034). The estimated frequency of AA prescriptions in Singapore is relatively low at 0.01%. The incidence of peanut and shellfish allergy in the Asian population appears to differ from that seen in Western populations.