Weak Evidence Supporting the Use of Steroids in the Emergency Management of Anaphylaxis

The use of corticosteroids for anaphylaxis or other severe allergic reactions is not associated with a reduction of relapses over the next week. Previous studies have found that — despite a lack of evidence to support the use — many emergency room physicians routinely employ such medications to prevent subsequent reactions.

Canadian researchers decided to investigate the strategy’s efficacy by tracking outcomes for patients treated for allergic reactions at 2 urban emergency departments.

First, they used hospital records to see how doctors at the 2 hospitals treated patients over a 5-year-period. Then, they used government records to see which patients returned to any emergency department or died within 7 days of initial treatment.

Physicians at the hospital emergency departments used corticosteroids in 48% of the 2,701 cases they treated. Those who received corticosteroids revisited an emergency department with allergic reactions in 5.8% of all cases while those who did not receive corticosteroids revisited in 6.7% of all cases. (No one from either group died.)

The difference, however, may have been due to chance (adjusted odds ratio [OR] 0.91; 95% confidence interval [CI], 0.64 to 1.28).

The researchers calculated that physicians would, on average, have to treat 176 patients with corticosteroids to prevent a single return to the emergency department, and they would also have to accept the possibility that treatment actually increased revisits. Indeed, the 95% CI estimate found that, in a best-case scenario, roughly 1 of every 39 patients would benefit from the treatment but, in a worst-case scenario, 1 of every 65 patients would be harmed by it.

Among the 473 patients who were diagnosed with anaphylaxis during their initial emergency department visit, corticosteroids were associated with slightly more allergy-related revisits over the next week but, again, the different was insignificant (OR 1.12; 95% CI, 0.41 to 3.27)

“Among emergency department patients with allergic reactions or anaphylaxis, corticosteroid use was not associated with decreased relapses to additional care within 7 days,” the study authors wrote in Annals of Emergency Medicine.

Anaphylaxis treatment guidelines in the U.S. and other countries note the widespread perception that corticosteroids, although far too slow acting to help in the treatment of acute anaphylaxis, can help prevent rebound anaphylaxis. Those guidelines also note that there’s little published evidence to support this perception.

Indeed, researchers who tried to marshal all the existing evidence for paper in the Cochrane Database of Systematic Review were unable to find a single randomized or quasi-randomized trial of corticosteroids against placebo, epinephrine, antihistamine or any combination of treatments.

“We conclude that there is no evidence from high quality studies for the use of steroids in the emergency management of anaphylaxis,” they wrote. “Therefore, we can neither support nor refute the use of these drugs for this purpose.”

Even retrospective analyses like the new paper from Canada are rare, so the authors of that paper believe their work will provide valuable insight to emergency department physicians, even if they did not find any significant evidence of either benefit or harm.