Aphthous stomatitis near to the ulcer, described histologically as "perivascular cuffing". Aphthous stomatitis has been classified as a type of non-infectious stomatitis (inflammation of the mouth). One classification distinguishes "common simple aphthae", accounting for 95% of cases, with 3–6 attacks per year, rapid healing, minimal pain and restriction of ulceration to the mouth; and "complex aphthae", accounting for 5% of cases, where ulcers may be present on the genital mucosa in addition to mouth, healing is slower and pain is more severe. A more common method of classifying aphthous stomatitis is into three variants, distinguished by the size, number and location of
Aphthous stomatitis and aphthous stomatitis is probably related to nutritional deficiencies caused by malabsorption. Less than 5% of people with RAS have Celiac disease, which usually presents with severe malnutrition, anemia, abdominal pain, diarrhea and glossitis (inflammation of the tongue). Sometimes aphthous-like ulcerations can be the only sign of celiac disease. Despite this association, a gluten-free diet does not usually improve the oral ulceration. Other examples of systemic conditions associated with aphthous-like ulceration include reactive arthritis, and recurrent erythema multiforme. Diagnosis is mostly based on the clinical appearance and the medical history. The most important diagnostic feature is a history of recurrent,