ALERT: Recognizing the Symptoms of a Rare Dermatological Condition with Systemic Effects

The following clinical case involves a dermatological disorder with broader health implications that should be considered in primary care settings.

A 55-year-old woman with a history of hypertension and COPD, who smoked 10 cigarettes daily and had no known allergies, had been taking enalapril for six years and formoterol via inhaler for two years. After her pulmonologist switched her inhaler medication to a combination of indacaterol and glycopyrronium due to worsening respiratory symptoms, she developed painful, red patches on her cheeks and neck on the second day of the new treatment. She also experienced a mild fever. The patient reported no recent changes in skincare products, diet, or sun exposure without protection, and had no recent cold-like symptoms.

She was urgently referred to dermatology, where the new inhaler was discontinued. A skin biopsy and blood tests—including a complete blood count, antibody screening, lupus anticoagulant, and serologies—were performed. She was started on oral corticosteroids.

Within 24–48 hours, her skin lesions improved and the pain decreased. Blood tests showed leukocytosis with neutrophilia, positive antibodies and lupus anticoagulant, and negative serologies.

Twenty days later, the skin biopsy confirmed Sweet syndrome.

Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is a skin condition marked by sudden, painful, red or purplish bumps or plaques, often on the face, neck, upper body, or hands. It is accompanied by systemic symptoms such as fever and elevated white blood cell counts, especially neutrophils. Diagnosis is based on clinical features and lab findings, including neutrophil infiltration in the skin without vasculitis.

The cause of Sweet syndrome is not fully understood but is thought to involve a hypersensitivity reaction triggered by infections, medications, or sometimes underlying cancers. It is more common in women and has been linked to various drugs, including contraceptives, antibiotics, antihypertensives, and—as in this case—inhaled respiratory medications.

Treatment with oral corticosteroids typically leads to rapid improvement. This case is notable for being the first reported instance of Sweet syndrome associated with an inhaler medication.

Although rare, Sweet syndrome should be considered in differential diagnoses, as it may signal infections, inflammatory conditions, or malignancies. A full workup is essential to rule out associated systemic illnesses.

Primary care providers should remain aware of rare diseases to ensure timely referral, accurate diagnosis, and appropriate treatment.

Ethical Compliance:
The authors confirm that no human or animal experiments were conducted for this study. Patient confidentiality was maintained, and informed consent was obtained for publication.