Table 5.

Differential diagnosis of RAS

Common
Traumatic Ulcer (Dental / Hard Bristle Tooth Brush)
Drugs (Nonsteroidal anti-inflammatory drugs, oral contraceptives, etc.)
Nutritional deficiency (iron, folate, zinc, vitamins such as B1, B2, B6, B12, and D3)
Viral ulcers (Coxsackie, Cytomegalovirus, Epstein-Barr virus, Human immunodeficiency virus)
Oral Mucositis (post-radiotherapy / chemotherapy)
Less Common
Dermatological conditions (Pemphigus vulgaris, erythema multiforme, drug-induced bullous pemphigoid, Steven Johnson Syndrome, Toxic Epidermal Necrolysis)
Hormonal disturbances (Addison’s disease, Hypo/Hyperthyroidism, Diabetes)
Autoimmune Disorders (Behcet’s Syndrome)
Inflammatory bowel disease
Rare
Bacterial infections (Tuberculosis, syphilis)
Fever syndromes (Cyclic neutropenia, PFAPA (Periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis) syndrome, Sweet syndrome, Familial Mediterranean fever, hyperimmunoglobulinemia D with periodic fever syndrome (HiDS))