In Reply In response to Dr DeLoughery’s concern about diphenhydramine, provided is a sensitivity analysis that excluded all anaphylaxis cases with the claim of “injection of diphenhydramine” (Table 1). Results are consistent with the primary analysis.
Regarding incidence rates, as discussed in our article, rates from our study were substantially lower than those reported from clinical trials of intravenous iron products. Although other study populations might have contributed to the observed differences, other differences in identifying and reporting anaphylaxis cases during clinical trials and during general clinical practice might also be relevant. Practicing physicians might not classify less severe or atypical anaphylactic cases as anaphylaxis; thus, the sensitivity of the anaphylaxis algorithm used in our study was probably low. We do not recommend comparing the crude incidence rates of anaphylaxis from this study with rates of other medications, especially if the latter estimates were based on different data sources or study methods.
Wang C, Wong S, Graham DJ. Risk of Anaphylaxis With Intravenous Iron Products. JAMA. 2016;315(20):2232-2233. doi:10.1001/jama.2016.0965