If sinus inflammation and infection spread via the upper aero-digestive tract mucosa, pharyngitis, laryngitis or tonsillitis may develop. The tract consists of the larynx, pharynx, oral cavity, nasal cavity, ear and paranasal sinuses.

Movement of mucopus, the mucus containing pus, to pharynx from the infected sinuses via the nasal airway is referred to as pharyngitis.  The most common symptom of pharyngitis is sore throat due to inflammation, which could be secondary to various upper respiratory infections, such as rhinitis. Sore throat is generally accompanied by cough, malaise, headache and rhinorrhea.

Both infectious and non-infectious factors may cause the sore throat. The non-infectious causes include postnasal drip, which is associated with sinusitis, exposure to smog or cigarette smoke, malignant disorders and low humidity. Viruses causing common cold are the most common agent triggering pharyngitis. For instance, rhinovirus is the predominate cause of pharyngitis. Allergy, infection or trauma can also trigger pharyngitis. Pharyngitis is quite often found in association with otitis and rhinitis.

Bacteria may also cause pharyngitis. Group A beta-haemolytic streptococcus (GABHS) is one of the main bacterial causes of pharyngitis. If GABHS-induced infection is not treated in time, complications, such as acute glomerulonephritis, peritonsillar abscess and acute rheumatic fever, may occur.

Other symptoms include inflammation of the pharynx’ mucous membranes and

infection or inflammation of the posterior oropharynx, soft palate, uvula and tonsils. Chronic sinusitis may cause lateral lymphoid bands’ hypertrophy, which means overgrowth or enlargement owing to expansion of the cells. The hypertrophy may be unilateral and affect the sinus.

Subepithelial lymphoid tissues cause granular pharyngitis, in which nodules are easily visible. Chronic sinusitis also causes granular pharyngitis or tonsillitis. Chronic pharyngitis includes chronic rhinitis, chronic nasopharyngitis and chronic pharyngitis. Acute pharyngitis encompasses sore throat without abscess, chronic pharyngitis due to viruses and streptococcal pharyngitis, and acute laryngopharyngitis.

Pharyngitis, an infectious disease, is more common in crowded places. The disease is more common in older children than younger children and infants. Most of the pharyngitis cases in adults are viral.

Laryngitis, one of the side effects of sinus infection, means irritation of vocal cords. Especially, recurrent or chronic laryngitis may be secondary to the infection and polyps.

Sinusitis may cause tonsillitis, inflammation of tonsils, and vice versa. Tonsils, lymphatic tissues, are prone to infections. Thus, timely treatment is necessary to avoid all side effects of sinus infection.