A Clinical Conundrum in Patients With a Common Clinical Spectrum but Rare Differentials: Hyper-Immunoglobulin E Syndrome and Idiopathic Eosinophilia.

Hyper-immunoglobulin E syndrome (HIES) and idiopathic eosinophilia lie on the same spectrum of immunodeficiency disease; therefore, physicians need to consider both possibilities as differential diagnoses for early identification. HIES is a primary immunodeficiency syndrome characterized by markedly elevated total IgE levels along with recurrent eczematous rash, skin infections, sinopulmonary infections, and multiple hospitalizations. Similarly, patients with idiopathic hypereosinophilic syndrome (HES) also present with marked eosinophilia, recurrent sinopulmonary infections, and evidence of organ damage such as eosinophilic myositis. Idiopathic eosinophilia also lacks any identifiable secondary aetiology and evidence of organ damage, with only eosinophilia in bone marrow. Both our cases have similar symptoms, presenting in the busy outpatient department settings that needed thoughtful consideration for the differentials. Awareness among Clinicians about this wide spectrum of differentials with overlapping presentations will facilitate early diagnosis and eventually enable optimal cost-effective treatment for patients.