What causes recurrent sore throat?

Recurrent sore throat—defined as experiencing three or more episodes of acute pharyngitis per year, or two or more episodes annually over consecutive years—can stem from a variety of underlying causes. Common infectious etiologies include recurrent viral upper respiratory infections (e.g., rhinovirus, influenza, Epstein–Barr virus), as well as bacterial infections such as group A Streptococcus (GAS), which may persist due to incomplete antibiotic treatment, asymptomatic carriage, or household transmission. Chronic tonsillitis, characterized by persistent inflammation and cryptic debris in the tonsillar tissue, is another frequent contributor.

Non-infectious causes must also be carefully considered. These include gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR), where acidic or non-acidic gastric contents irritate the pharyngeal mucosa—often presenting without classic heartburn. Environmental irritants (e.g., tobacco smoke, dry air, occupational dust or fumes), allergic rhinitis with postnasal drip, and chronic sinusitis can similarly provoke persistent or recurrent throat discomfort. Less common but important considerations include immunodeficiency states (e.g., IgA deficiency, HIV), autoimmune conditions (e.g., granulomatosis with polyangiitis, Sjögren syndrome), and, rarely, malignancy—particularly in individuals with risk factors such as tobacco use, heavy alcohol consumption, or persistent unilateral symptoms.

A thorough evaluation is essential and typically includes a detailed history (e.g., timing, triggers, associated symptoms like fever, dysphagia, weight loss, or voice changes), physical examination focusing on oropharyngeal structures and cervical lymph nodes, and targeted investigations—such as rapid antigen detection tests or throat cultures for GAS, serologic testing for EBV or HIV when indicated, and endoscopic assessment if structural abnormalities or asymmetry are suspected. Management is tailored to the underlying cause and may involve antimicrobial therapy, acid suppression, allergen avoidance, smoking cessation, or referral for surgical evaluation (e.g., tonsillectomy in appropriately selected patients meeting Paradise criteria).