Aphthous Ulcers Workup

Updated: Dec 28, 2022
  • Author: Jaisri R Thoppay, DDS, MBA, MS; Chief Editor: Arlen D Meyers, MD, MBA  more...
  • Print

Approach Considerations

It is important to rule out any underlying cause in the case of oral ulcers. A thorough history is essential, since this and a review of systems can assist the clinician in determining whether ulcers are related to a systemic inflammatory process or are truly idiopathic. Diseases causing oral ulcers that should not be mistaken for recurrent aphthous stomatitis (RAS) include Behçet syndrome, cyclic neutropenia, recurring intraoral herpes infections, human immunodeficiency virus (HIV)–related oral ulcers, and gastrointestinal diseases such as Crohn disease and ulcerative colitis. Minor aphthous ulcers (MiAUs) most commonly form on nonkeratinized oral mucosa, usually on the buccal and labial mucosa; they have a duration of about 10-14 days without scar formation. [2]


Laboratory Studies

See the list below:

  • Systemic disorders should particularly be suspected in the presence of features that may suggest a systemic background.

  • Diagnosis of recurrent aphthous stomatitis (RAS) is based on history and clinical features. No specific tests are available; however, to exclude systemic disorders discussed above, the following tests may be helpful:

    • Complete blood cell count

    • Hemoglobin test

    • White blood cell count with differential

    • Red blood cell indices

    • Iron studies (usually an assay of serum ferritin levels)

    • Red blood cell folate assay

    • Serum vitamin B-12 measurements

    • Serum antiendomysium antibody and transglutaminase assay (positive in celiac disease)

  • Rarely, biopsy may be indicated in cases in which a different diagnosis is suspected. Occasionally, for example, pemphigus may mimic RAS. Occasional RAS can mimic a neoplasm, necrotizing sialometaplasia, or TUGSE (traumatic ulcerative granuloma with stromal eosinophilia).


Histologic Findings

The histology of RAS is nonspecific. The ulcer is depressed well below the surface, and the inflammation extends deeply. The surface of the ulcer is covered by a fibrinous exudate infiltrated by polymorphs. Beneath is a layer of granulation tissue with dilated capillaries and edema. Deeper still is a repair reaction, with fibroblasts in the surrounding connective tissue laying down fibrous tissue.