<s>[INST] hello, i have a problem with sinus. Every time the doctor gives antihistamines and pain relief tabs and antibiotics. But he says i shouldnt get allegy test. but the condition keeps occuring again and again. But he says i dont have allergies, if thats the case, why does he prescribe antihistamines? [/INST] Hello,I can't comment on your case because I don't have enough information to do so. I can explain why antihistamines may help though. Antihistamines do act against allergic reactions but they also reduce the amount of nasal discharge. A runny nose may become dry. Patients with nasal and sinus problems usually benefit from reduced nasal discharge.I hope I've answered your question. Please let me know if you need further assistance.Kind Regards,Dr Panagiotis Zografakis,Internal Medicine Specialist </s>