Oral Ulcers - DDx

1. Aphthous Ulcers (aka Canker Sores) – painful shallow, round-oral ulcers with grayish base, often on the buccal mucosa.  Most common cause of mouth ulcers in the U.S., more common in childhood/adolescence, can get multiple outbreaks/year.  Pathogenesis is not well understood but thought to involve alterations in local cell-mediated immunity. 
Predisposing Factors: Stress, hormonal changes, infections, neutropenia, methotrexate and other meds, HIV (increased incidence with decreasing CD4), Vitamin and Mineral Deficiencies (B vitamins, iron, folic acid, zinc)

2. Infections:
- HSV – usually HSV-1, more commonly due to recurrent infection vs primary.  Dx made by Tzanck smear showing multinucleated giant cells, but also DFA and viral culture.
- VZV – can present similarly to HSV
- Coxsackie Virus – usually in children, causes Hand-Foot-Mouth Disease, often with fever and other URI symptoms
- Syphilis
- HIV (primary infection) – but also predisposes to other infections that cause oral ulcers (HSV, VZV, CMV, candida, syphilis , etc) as well as aphthous ulcers

3. Autoimmune
- Behcet’s Disease – recurrent oral and genital ulcers
- SLE – usually painless oral ulcers
- Reactive Arthritis
- Bullous pemphigoid – has oral involvement in 1/3rd of cases, as well as blisters in the flexural areas, groin, axillae
- Pemphigous Vulgaris – flaccid bullae which usually begin in the oropharynx
- Erythema Multiforme and Stevens Johnson Syndrome

4.  Contact or Irritant Stomatitis – e.g. from various types of toothpastes and other chemicals

5.  Chemotherapy-related Mucositis – can affect part or all of the GI tract: symptoms can include oral ulcers, dysphagia, odynophagia, gastritis, diarrhea,  malabsorption

(Chanu Rhee MD, 12/16/10)