A Diagnosis of Idiopathic Hypereosinophilic Syndrome With Skin Involvement in a Patient Presenting With Lymphadenopathy and Rash.

Idiopathic hypereosinophilic syndrome is a rare entity where the diagnosis is made after all the probable causes of hypereosinophilia are excluded. The characteristic organ involvement includes the heart, nervous system, lung, and gastrointestinal tract. The mainstay of treatment is corticosteroids. Patients who are unresponsive to the steroids require immunomodulatory therapy that includes imatinib, mepolizumab, and in some resistant cases alemtuzumab. We describe a case of idiopathic hypereosinophilic syndrome with skin involvement without other organ infiltration in a previously unevaluated South Asian male who responded well to the initiation of steroid therapy.