Hello I appreciate your concern for your husband Looking at his history this could be URTI like pharyngitis or sinusitis caused by viral infection I would advise you get few investigations done for him like blood for Hemoglobin, CBC, Liver function test X ray Chest and PNS (paranasal sinuses) In my opinion you should take anti allergic drugs and a cough syrup Ask him not to smoke until he gets well completely Gargling with Warm saline water or antiseptic mouth wash is recommended Multivitamin supplements like vitamin C and B complexes if it persists or worsens further please consult an ENT surgeon for examination and subsequent treatment. Hope this helps him thanks