AFRS may affect immunocompetent individuals — meaning people with normally functioning immune systems but who have an underlying allergic sensitivity. It's more commonly observed in people who:

• Have a history of atopic disease particularly allergic rhinitis or asthma
• Live in warm, humid climates with high environmental mold counts
• Have existing chronic rhinosinusitis or nasal polyps

Young to middle-aged adults are most affected, though AFRS can occur at any age.
It can happen in both men and women, although some studies suggest a slightly higher incidence in men.