Cervical Paraspinal Pyomyositis Arising From Severe Allergic Contact Dermatitis to Hair Dye

A 70-year-old woman presented to the emergency department with painful posterior neck swelling and fever. Examination demonstrated a large, inflamed plaque across her posterior neck. Diagnostic evaluation revealed cervical paraspinal pyomyositis from methicillin-resistant Staphylococcus aureus as a likely complication of relative immunosuppression and significant excoriation from severe allergic contact dermatitis to p-phenylenediamine, a chemical found in hair dye. This case highlights the importance of considering pyomyositis as a potential diagnosis in patients presenting with painful muscle swelling and fever in the setting of significant skin abrasion and excoriation.