Eosinophilia is a challenge to our everyday clinical practice. There are multiple causes to consider when diagnosing eosinophilia, and drug hypersensitivity must be taken into account. It is especially difficult to manage it in hospitalized patients with multiple complications and infections. Allergy tests are not always as helpful as we would like, so we rely on clinical observation and laboratory analysis to establish our diagnosis. We present a unique clinical case because the same patient presented two clinical episodes of eosinophilia after the administration of Carbapenems in the context of abdominal infection.