2nd order laboratory parameters – depending on the results of the history, physical examination and obligatory laboratory parameters – for differential diagnostic clarification.
- Serological and microbiological tests (HIV, CMV, Chlamydia trachomatis, lymphogranuloma venerum, Neissereia gonorrhoea, histoplasmosis, leishmaniasis).
- Biopsy (tissue sampling) – if Crohn’s disease is suspected.