A Challenging Case of Idiopathic Hypereosinophilic Syndrome: An Itching in the Brain.

Hypereosinophilia (HE) has various causes and treatment remains a challenge when there is no relief to symptoms and a decrease in the eosinophil count. Such cases need extensive laboratory support, but the cause may remain obscured in some cases. This is a case of a 58-year-old known diabetic and hypothyroid female who initially presented with fever secondary to pyelonephritis and later developed severe itching and extensive skin hyperpigmented lesions. The laboratory findings were a persistently elevated eosinophil count and generalized itching that was refractory to treatment. The presentation of episodes of itching was like Gleich syndrome without angioedema and needed an injection of hydrocortisone and chlorpheniramine maleate to treat. Diethylcarbamazine, hydroxyurea, and steroids failed to decrease the eosinophilia as well as the episodic itching. We conducted an extensive workup for mutation studies. The bone marrow eosinophil count was above 20%. Considering it as idiopathic non-steroid-responding HE, imatinib was started, and the patient immediately responded, and the eosinophil count came within the normal range within one month. She has been followed up and closely monitored for the past 1 to 1.5 years with no relapse of symptoms and no rise in the eosinophil count.