Background: Drug reactions have been associated with increased blood eosinophil levels.
Objective: To review clinical characteristics, the diagnosis, and the management of drug-induced eosinophilia.
Methods: Pertinent articles were selected and reviewed in relation to a case presentation of drug-induced eosinophilia.
Results: A case of asymptomatic eosinophilia in the setting of acetylsalicylic acid (aspirin) use was presented, followed by discussion of the clinical characteristics, diagnosis, and management of drug-induced eosinophilia. Clinical pearls and pitfalls were reviewed for the practicing allergist, clinical immunologist, and fellow-in-training.
Conclusion: Drug-induced eosinophilia is a diagnosis of exclusion. Although most cases of drug-induced eosinophilia are asymptomatic, one study showed an increased rate of hypersensitivity reactions in patients with higher eosinophil counts and earlier onset of eosinophilia.