Aphthous Ulcers Workup

Updated: Jan 20, 2017
  • Author: Crispian Scully, MD, MRCS, PhD, MDS, CBE, FDSRCS(Eng), FDSRCPS, FFDRCSI, FDSRCSE, FRCPath, FMedSci, FHEA, FUCL, FSB, DSc, DChD, DMed(HC), Dr(HC); Chief Editor: Arlen D Meyers, MD, MBA  more...
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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.