2nd order laboratory parameters – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification
- Small blood count
- Differential blood count
- Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
- HIV test
- Smear for herpes simplex virus, biopsy (if herpes simplex virus negative) – in case of majoraphthae, herpetiform aphthae or complex aphthosis.
- ANA (antinuclear antibodies) – in suspected rheumatic diseases.
- Micronutrient analysis – on suspicion of malnutrition (iron, folic acid, vitamin B1, B2, B6, B12 deficiency).
- Biopsy (tissue sampling) – indication:
- Unclear oral mucosal change that does not show a tendency to regress after observation or therapy for 2 weeks.
- In the case of “large, persistent lesions […] in order to identify an alternative cause” [S2k guideline]
- Exclusion of squamous cell carcinoma and its precursor lesions.
Note: Biopsy should be performed from the marginal wall area as in other ulcerative processes.
