Chronic rhinitis may lead to inflammation of the mucous membrane of the sinuses of the skull due to spread of infection from the nose.
The maxillary sinuses are most frequently affected whereas frontal sinuses are affected less frequently. Nasal infection due to nasal obstruction, nasal allergy, habit of forcible blowing of the nose, water entering the nose forcibly during diving, baro trauma, dental infection, trauma are common causes of sinusitis.
It causes headache and tenderness over the sinuses. Headache is aggravated while bending down, coughing and sneezing. Discharge from frontal sinus appears in upright position while that from maxillary sinus appears when patient lies down in his unaffected side.