How to Treat Mouth Sores (Canker Sores)

Recurrent aphthous stomatitis—commonly known as canker sores—is one of the most frequent oral mucosal disorders encountered in clinical practice. These painful, shallow, round or oval ulcers typically appear on non-keratinized oral surfaces such as the buccal mucosa, labial mucosa, tongue, floor of the mouth, and soft palate. They are not contagious and are distinct from herpes simplex virus–induced lesions.

Management focuses on symptom relief, accelerating healing, and reducing recurrence frequency. First-line interventions include topical corticosteroids—such as triamcinolone acetonide 0.1% dental paste or fluocinonide 0.05% gel—applied directly to the ulcer two to four times daily. Over-the-counter options like benzocaine or lidocaine gels provide transient analgesia but do not alter disease course. For larger, persistent, or multiple ulcers, short-course systemic corticosteroids (e.g., prednisone 20–40 mg/day for 3–5 days) may be warranted under medical supervision.

Adjunctive strategies include rigorous oral hygiene with alcohol-free antimicrobial mouth rinses (e.g., chlorhexidine gluconate 0.12%), avoidance of known triggers—including sodium lauryl sulfate–containing toothpaste, acidic or spicy foods, mechanical trauma, and nutritional deficiencies (notably iron, folate, vitamin B₁₂, and zinc)—and correction of underlying systemic conditions such as celiac disease, inflammatory bowel disease, or Behçet syndrome when identified.

Patients experiencing more than three episodes per month, ulcers lasting longer than three weeks, or lesions associated with systemic symptoms (e.g., fever, weight loss, genital ulcers, or ocular inflammation) should undergo comprehensive evaluation to exclude secondary causes or complex aphthosis. Early referral to an oral medicine specialist or dermatologist is recommended in such cases.