This is a well documented warning of antihistamines; if you have an infection you should not use them. And you should definitely not continue use after 3 days

This is a well documented warning of antihistamines; if you have an infection you should not use them. And you should definitely not continue use after 3 days with no improvementn in symptoms. You also should avoid using steroids when you have an infection (many antihistamines are steroids) (unless you're fighting the immune response). The risks increase more with fungal infections than bacterial or viral. (So much that it was a popular trope in House MD that if it was fungal or the infection was causing sepsis then the steroids would kill the patientl https://www.healthline.com/health-news/overuse-of-steroid-medications-can-increase-risk-of-certain-infections https://www.healthline.com/health-news/overuse-of-steroid-me...