<s>[INST] My dentist said I had some gum disease so I started to use a lot of mouthwash with chlorhexidine gluconate. I started sneezing a lot with lots of thin watery running nose with very sore inside nostrils. Could this be allergic reaction to mouthwash? I am 50 years, female, good health, 65 kilo, 171cm. [/INST] HI, thanks for using Chat Doctor It is possible to have an allergic reaction to any chemical agent. It is possible that your response is related to the use of the chlorohexidine if there have been no other changes. You can try to eliminate it for a few days to see if the reaction ceases. If it continues then it isl likely that the reaction in not related and there is another source. Allergy testing can help to identify the cause. This can be done by skin prick testing or blood tests. The use of oral anti histamines would help to reduce the reaction. I hope this helps </s>