The practice of using corticosteroids to treat anaphylaxis appears to have derived from management of acute asthma and croup. Indeed, as you point out, the use of corticosteroids in anaphylaxis has been called into question. A practice parameter update in 2015 by Lieberman et al includes an excellent discussion about the topic. After reviewing the published evidence, the authors state that the use of corticosteroids has no role in the acute management of anaphylaxis. The report notes that the time to onset of corticosteroid effect is too slow to prevent severe outcomes, such as cardiorespiratory arrest or death, which tend to occur within 5-30 minutes for allergens such as medications, insect stings and foods. They also state that patients with complete resolution of symptoms after treatment with epinephrine do not need to be prescribed corticosteroids.
According to the practice parameter update and another recent review, the evidence that corticosteroids reduce or prevent biphasic reactions is weak. In 2017, Alqurashi and Ellis published a review about whether corticosteroids are useful in acute anaphylaxis and also whether they prevent biphasic reactions. Since randomized controlled studies of these topics are lacking, 31 observational studies (which were quite heterogeneous) were reviewed. Their conclusions are consistent with the 2015 practice parameter update: corticosteroids are highly unlikely to prevent severe outcomes related to anaphylaxis. They also reviewed 22 studies that specifically addressed the association of corticosteroids with biphasic anaphylaxis and only 1 study suggested a beneficial effect. It showed that biphasic reactors tended to receive less corticosteroid; however, this association was not statistically significant. Studies using different corticosteroid formulations in biphasic reactions have not demonstrated any differences.
Whether epinephrine administration could benefit subgroups of patients with co-morbid conditions such as asthma is not known.
1. Lieberman P et al. Anaphylaxis-a practice parameter update 2015. Ann Allergy Asthma Immunol 115(2015):341-84.
2. Campbell RL et al. Emergency department diagnosis and treatment of anaphylaxis. 2013. Ann Allergy Asthma Immunol. 2014;113:599-608.
3. Alqurashi W and Ellis AK. Do corticosteroids prevent biphasic anaphylaxis? J Allergy Clin Immunol Pract 2017;5:1194-205.
I hope this answer is helpful to you.
Jacqueline A. Pongracic, MD, FAAAAI