Hi, As per your query thrush after taking steroid inhalers can be most probably due to yeast infection known as Oral Thrush and is caused by candida albicans fungus. Boric acid can be used to gargle for thrush but the solution should be very much dilute and should not be swallowed. I would however suggest that you should consult an Oral Physician and get evaluated and in case if thrush is confirmed as the cause he can advise you to gargle with Nystatin mouthwash, suck on anti-fungal lozenges and take more of probiotics like yoghurt and garlic. If it does not improve in 15 days oral anti-fungals like Fluconazole or Itraconazole can be advised. You should drink plenty of water as thrush can cause dry mouth. Avoid antimicrobial mouthwash. Maintain a good oral hygiene. Hope this information helps. Let me know if I can assist you further. Thanks and regards, Dr. Honey Nandwani Arora