Drug-associated eosinophilic fasciitis: A case of eosinophilic fasciitis secondary to cemiplimab therapy

Abstract

Patient: Female, 72-year-old Final Diagnosis: Drug induced eosinophilic fasciitis Symptoms: Joint pain • skin discoloration and induration Medication: — Clinical Procedure: Skin biopsy Specialty: Rheumatology Objective: Background: Case Report: Conclusions: Rare disease Eosinophilic fasciitis, also known as Shulman syndrome, is a rare inflammatory condition characterized by diffuse erythema and progressive collagenous thickening of the subcutaneous fascia. The underlying cause re-mains to be definitively established; however, several drugs have been linked to this uncommon clinical enti-ty. We present a rare case of eosinophilic fasciitis secondary to immune checkpoint inhibitor therapy. A 72-year-old woman with metastatic cutaneous squamous cell carcinoma presented to the rheumatology clin-ic for evaluation of joint pain that developed 3 weeks after beginning treatment with cemiplimab. The correla-tion of clinical history and physical examination was most consistent with osteoarthritis. Symptoms improved after a short course of low-dose prednisone. The patient continued cemiplimab therapy for approximately 1 year and was subsequently transitioned to carboplatin and radiation therapy. However, relapse occurred short-ly thereafter, and cemiplimab was restarted. Two weeks later, the patient developed severe joint pain, morn-ing stiffness, and extensive cutaneous discoloration and induration. A skin biopsy was performed. Microscopic examination of a tissue sample showed a mononuclear infiltrate with plasma cells and eosinophils. A diagnosis of eosinophilic fasciitis was established. Cemiplimab was held and the patient was treated with hydroxy-chloroquine, prednisone, and sulfasalazine. Symptoms improved within 1 week. Eosinophilic fasciitis is a rare but important adverse effect of immune checkpoint inhibitors. Individuals receiv-ing immunotherapy should be monitored closely for symptoms of eosinophilic fasciitis, as prompt treatment is essential to prevent long-term complications.