aphthous

Aphthous refers to aphthous ulcers, commonly known as canker sores, which are small, painful lesions of the oral mucosa. Recurrent aphthous stomatitis (RAS) is the most familiar condition described by this term and is characterized by episodic appearances of ulcers on non‑keratinized mucosa such as the inner lips and cheeks, the floor of the mouth, the soft palate, and the dorsal surface of the tongue.

There are three clinical types: minor ulcers (the most common), major ulcers (larger and deeper, with slower healing and possible scarring), and herpetiform ulcers (numerous small ulcers that may coalesce). Minor aphthae typically measure 3–10 mm and heal within one to two weeks without scarring. Major aphthae exceed 1 cm and can take weeks to months to resolve. Herpetiform ulcers are usually 1–3 mm and can appear in clusters.

Etiology is multifactorial and not fully understood. Contributing factors may include immune dysregulation with T-cell–mediated mucosal attack, genetic predisposition, stress, local trauma, hormonal changes, and nutritional deficiencies (iron, vitamin B12, folate, zinc). Associations with systemic conditions such as celiac disease, Crohn disease, and ulcerative colitis have been described. The condition is not contagious.

Diagnosis is typically clinical, based on history and appearance. In recurrent or atypical cases, evaluation for nutritional deficiencies, hematologic abnormalities, or underlying systemic disease may be undertaken, and differential diagnoses include oral herpes simplex infection and traumatic ulcers.

Management focuses on symptom relief and shortening duration. Options include topical corticosteroids (eg, triamcinolone paste, clobetasol), topical anesthetics, protective pastes, antiseptic rinses (chlorhexidine), and oral rinses. Severe or persistent cases may require intralesional steroids or systemic therapies (eg, colchicine, dapsone) and evaluation for underlying conditions. Most minor aphthae heal spontaneously in 1–2 weeks; major and persistent ulcers require closer follow‑up.