Randomized controlled trial of topical aspirin in the treatment of bee and wasp stings

The New South Wales Poisons Information Centre (NSW PIC) has been recommending the use of topical aspirin paste for bee and wasp stings since the early 1980s. Anecdotal evidence from calls suggested it was effective in reducing the swelling and duration of pain, but a literature search found no evidence to support this.

The objective of this study was to assess the effectiveness of advice given by a PIC to apply topical aspirin for the treatment of bee and wasp stings.

Patients were recruited from callers to the NSW PIC who reported a bee or wasp sting. They were randomly assigned, using a 2:1 ratio, to two different treatment advices: to apply an ice pack (control group), or to apply an ice pack and topical aspirin paste (treatment group). Initial follow-up was within 24-48 hours. Primary outcome was the presence of swelling at 12 hr. Secondary outcomes included the presence of pain at 12 hr, the presence of itchiness, and duration of redness.

There were 37 patients who received treatment advice and 19 in the control group. Of the 37 patients advised to apply aspirin, 21 (57%) had no swelling at 12 hr compared with 14 of the 19 (74%) patients with ice alone (difference -17%; 95% CI: -47-12%; p = 0.26). Eighty-one percent (30/37) of patients advised to apply aspirin had no pain at 12 hr compared with (18/19) 95% of the others (-14%; 95% CI: -39-14%; p = 0.34). The median duration of redness was 6 hr [interquartile range (IQR): 2-48 hr] in those advised to apply aspirin paste compared with 2 hr (IQR: 0-10 hr) in those that only applied ice (p = 0.04).

Topical aspirin paste was not effective in reducing the duration of swelling or pain in bee and wasp stings, and significantly increased the duration of redness. Symptoms rapidly subsided with ice alone as treatment.