Steroid resistant hypereosinophilic syndrome found to be Hodgkin’s Lymphoma

Hyperoeosinophilic syndrome (HES) is rare, and clinicians may not recognize its potential association with malignancy. Red flag signs of HES include steroid resistance, older age, and significant lymphadenopathy that can be indicative of malignancy. In this case, an elderly male presenting with right chest wall erythema and axillary lymphadenopathy was initially diagnosed with and treated for cellulitis. Labs were significant for hypereosinophilia. Evidence of end organ damage raised concern for HES. Over the course of three hospitalizations, he was found to have a rising eosinophil count despite high-dose corticosteroid treatment. Further investigation eventually revealed a diagnosis of Hodgkin’s Lymphoma. This case highlights steroid-resistant HES as a presenting sign of malignancy and allows for discussion of potential investigative approaches for HES therapy. Though corticosteroids are first-line treatment for hypereosinophilia and HES, they are well known to have many adverse effects. Biologics, such as mepolizumab and benralizumab, have more acceptable side effect profiles and are effective in treating non-myeloid HES.  The use of biologics as first-line treatment for HES has yet to be investigated.