[Idiopathic and secondary recurrent aphthous stomatitis: A narrative review].

Recurrent aphthous stomatitis (RAS) is the most common cause of painful ulcers of the oral mucosa, affecting approximately 10 to 20% of the population. It is characterized by recurrent, well-demarcated superficial ulcers located on non-keratinized mucosa, which heal spontaneously within one to two weeks. Three clinical subtypes are classically described: minor aphthae (the most common form), major aphthae, and herpetiform aphthae. Diagnosis is primarily clinical, but it is essential to rule out other causes of oral ulcers (traumatic, infectious, autoimmune, neoplastic) and to identify secondary causes of RAS (e.g., Behçet's disease, inflammatory bowel disease) to avoid diagnostic delay, detect specific complications, and tailor management appropriately. The pathophysiology of RAS involves an inappropriate cell-mediated immune response in genetically predisposed individuals. Reported abnormalities affect both innate immunity (notably neutrophils) and adaptive immunity (CD8+ T lymphocytes, Th1/Th17 profile). Precipitating factors such as nutritional deficiencies, psychological stress, microtrauma, or food intolerances may trigger flare-ups. Management is based primarily on general measures and local treatments. Severe or refractory cases may require a short course of systemic corticosteroids or maintenance therapy (e.g., colchicine, apremilast). This narrative review provides an update on recurrent oral aphthosis.