A case of exemestane induced pseudocellulitis

Exemestane is an aromatase inhibitor increasingly incorporated into the treatment of hormone sensitive breast cancer. Pseudocellulitis describes an uncomplicated inflammation of the dermis and hypodermis from a noninfectious etiology. It presents with erythema, swelling, warmth and tenderness of the affected skin. We report a case of a 47-year-old Indian woman who presented with 2-day history of redness and swelling of her left lower limb. There were no other symptoms. She was recently switched from tamoxifen to aromasin as adjuvant treatment for her breast cancer. Examination revealed erythema, edema, and warmth over the left lower limb. Laboratory investigations and doppler ultrasound scan were unremarkable. Skin punch biopsy showed dermal inflammatory infiltrate composed of lymphocytes, histiocytes and scattered eosinophils and neutrophils, concentrated in the superficial and deep perivascular regions suggestive of a leukocytoclastic vasculitis. The diagnosis of exemestane induced leukocytoclastic vasculitis presenting as pseudocellulitis was made. She was given a course of systemic and topical steroids with completere solution of lesion within 2 weeks. This is the first reported case of exemestane induced pseudocellulitis to our knowledge. Dermatologists and clinicians should be aware of this peculiar adverse drug reaction to avoid misdiagnosis and prevent unnecessary treatment.