Why would my doctor prescribe Fluticasone inhaler for a sinus infection?

It's a corticosteriod to help with swelling and inflammation. It should be used for at least 2-3 weeks to see if it improves

Fluticasone can be used for swelling and inflammation as a nasal spray for sinus problems along with an antibiotic as it contains a steroid. It is usually prescribed as a nasal spray though and not an inhaler so i wonder if she ordered it wrong or the pharmacy filled it wrong. It takes a few days to a few weeks for this anti-inflammatory action to occur so you may not have used it long enough to see results. If it caused a rash however, you were best off to stop it although it may be questionable as to whether it was the spray or the antibiotic. If you have discontinued use of the fluticasone and have worsening of the rash, I would also discontinue the antibiotic and call your Dr right away or go to the ER if you have any swelling of your lips, tongue or have difficulty breathing.