Aphthous-like ulcers : resembles recurrent aphthous ulcers in characteristics but associated with underlying systemic disorder. Consider underlying condition if ulcer first occur later in life, affect atypical sites e.g. palate or gums, affect extra oral sites e.g. genitalia or with systemic features. Conditions with aphthous are VIT B12 deficiency, folate deficiency, iron deficiency, coeliac disease, ulcerative colits. Behcet's syndrome, reiter's syndrome, immunodeficiency, Epstein-Barr virus infection