Sweet Syndrome, also known as acute febrile neutrophilic dermatosis, is a rare inflammatory skin disorder with systemic manifestations. Although uncommon, it is critical for primary care physicians to recognize its clinical signs and consider it during differential diagnosis—especially when symptoms rapidly follow medication changes.

This article outlines a documented clinical case and offers a comprehensive review of Sweet Syndrome, including its presentation, diagnostic criteria, treatment, and clinical significance, particularly in relation to medication-induced reactions.

Clinical Case Summary

A 55-year-old female patient with a medical history of hypertension and chronic obstructive pulmonary disease (COPD) presented with erythematous, painful facial and neck lesions accompanied by low-grade fever. She had no known allergies and reported smoking approximately 10 cigarettes daily.
Her regular medication regimen included:

Enalapril (6 years)
Inhaled formoterol (2 years)
Due to a deterioration in pulmonary function, her pulmonologist replaced formoterol with a combination of indacaterol and glycopyrronium in capsule inhaler form.

On the second day of the new therapy, the patient developed painful, reddish skin lesions on her cheeks and neck, prompting a visit to her primary care clinic. She denied recent upper respiratory infection symptoms, had used appropriate sun protection, and made no changes to her diet or cosmetic routine.
Referral and Diagnostic Workup

Given the sudden onset and severity of symptoms, the patient was referred urgently to the Dermatology Department. The specialist recommended discontinuation of the new inhaled medication, conducted a skin biopsy, and ordered laboratory testing, including:
Complete blood count (CBC)
Autoimmune panel (e.g., antinuclear antibodies)
Lupus anticoagulant
Infectious serology
Initial labs showed:
Leukocytosis with neutrophilia
Negative autoimmune serology
No signs of infection
Corticosteroid therapy was initiated. Within 24 to 48 hours, the lesions improved significantly and pain diminished.