Eosinophilic Dermatosis of Hematologic Malignancy.

Eosinophilic dermatosis of hematologic malignancy (EDHM) is a rare chronic skin condition commonly affecting individuals with underlying hematologic malignancies, most notably chronic lymphocytic leukemia (CLL). EDHM presents as pruritic, insect-like bites, but without patient-reported contact/bites of insects. We present a case of a 44-year-old male who presented to Elkhorn Dermatology with a scaly rash and serpiginous borders on the nasal tip and right cutaneous upper lip. The patient was diagnosed with CLL one year prior and had been on zanubrutinib for 10 days since presenting to the dermatology clinic. Initial treatment with antifungal and antibiotic therapies showed no improvement, leading to a punch biopsy that revealed perivascular and periadnexal lymphocytic dermatitis with eosinophils. This finding, along with the patient's underlying CLL, led to a diagnosis of EDHM. This case highlights the diagnostic challenges and therapeutic complexities associated with EDHM in patients with hematologic malignancies.