Autosomal dominant hyper IgE syndrome (AD-HIES) is a primary immunodeficiency caused by loss-of-function (LOF) mutations in the Signal Transducer and Activator of Transcription 3 (STAT3) gene. In these patients, performing a correct differential diagnosis of pulmonary infections is difficult and challenging, as they usually have atypical presentations. However, establishing a correct diagnostic and therapeutic approach is essential, as pulmonary complications are responsible for high morbidity and mortality rates in these patients. We report the case of a teenage girl with AD-HIES and respiratory symptoms and fever in whom performing a correct differential diagnosis was challenging.