Most patients with chronic respiratory diseases like COPD rely on inhalers, which are considered safe and effective. Side effects are usually mild, but a rare case has drawn medical attention after a woman developed Sweet syndrome—an uncommon inflammatory skin disorder—shortly after starting a new inhaler.
The 55-year-old patient, with a history of hypertension and COPD, had been stable on formoterol for years. When her lung function worsened, she was switched to a combination inhaler containing indacaterol and glycopyrronium. Within 48 hours, she developed painful, bright red plaques on her face and neck, along with a low-grade fever. No other causes were identified, and a biopsy confirmed Sweet syndrome.
Treatment with oral corticosteroids led to rapid improvement, with fever subsiding and skin lesions healing within days. Sweet syndrome, first described in 1964, is typically triggered by infections, cancers, or medications—though inhaled therapies have not been reported until now.
This unusual case underscores the importance of vigilance when prescribing. While inhalers remain overwhelmingly safe, clinicians should recognize that even common therapies can rarely cause unexpected immune reactions.
