A short course of oral corticosteroids in children with acute asthma may temporarily depress immune response to a new antigen, but this situation resolves within six weeks and has no apparent impact on response to known antigens.

Researchers studied 27 children, aged 3-17 years treated with oral corticosteroids and 14 who were unexposed to such agents. On presenting with acute asthma to the emergency department of a tertiary-care pediatric hospital, each youth was immunized with three antigens: a neoantigen, Bacteriophage Phi _ 174; and two recall antigens (diphtheria and tetanus). The children were reimmunized with Bacteriophage after about five weeks.

According to the authors, the results apply primarily to afebrile children receiving a five-day course of oral prednisolone in the treatment of an asthma exacerbation: In the corticosteroid users, adjusted total (immunoglobulin [Ig]G and IgM) peak titers to the primary Bacteriophage immunization was 85% lower than that displayed by the controls. However, no significant differences were seen between the groups after the second Bacteriophage immunization. No differences between groups were seen in the rise of diphtheria or tetanus antibodies.

Although additional research is needed to confirm these findings, “Our results support the possibility of a transient immune suppression when systemic steroids are administered while the child is mounting a primary immune response to a new antigen, with no sustained immunosuppression,” wrote the authors in Pediatric Allergy, Immunology, and Pulmonology (2010;23:243-252).