What is the key reason for rinsing the mouth after using a corticosteroid inhaler?

Rinsing the mouth after using a corticosteroid inhaler is crucial primarily to avoid fungal infections, particularly oropharyngeal candidiasis. Corticosteroids can alter the normal flora in the oral cavity and suppress local immune responses, making it easier for opportunistic pathogens like Candida albicans to thrive. By rinsing the mouth, the residual medication is washed away, reducing the likelihood of fungal overgrowth and subsequent infection.

While minimizing bad breath, improving systemic absorption, or removing residue may seem relevant, they do not address the key concern associated with inhaled corticosteroids. The primary focus of mouth rinsing is to mitigate the risk of candidiasis and maintain oral health.