This clinical case describes a 55-year-old woman with hypertension and COPD who developed painful erythematous plaques on the face and neck with low-grade fever shortly after starting a new inhaled COPD treatment (indacaterol/glycopyrronium). Laboratory tests showed leukocytosis with neutrophilia, and skin biopsy confirmed Sweet syndrome (acute febrile neutrophilic dermatosis). Symptoms improved rapidly after discontinuation of the drug and initiation of oral corticosteroids.

Sweet syndrome is a rare neutrophilic dermatosis characterized by sudden-onset painful erythematous plaques, fever, and systemic findings. Although its exact cause is unclear, it is often associated with infections, autoimmune diseases, malignancies, or drug exposure. Many medications have been linked to the condition, but this appears to be the first reported case associated with inhaled therapy.

The case highlights the importance of considering rare diagnoses in primary care, recognizing drug-related triggers, and completing investigations to rule out systemic disease, as Sweet syndrome may signal serious underlying conditions.