In June, 2004, a 35-year-old white woman was referred to our hospital complaining of a painful area on her vulva. Her symptoms had been present for 1 week and she had lost 3 kg in weight in that time. Her medical history showed no relevant details with the exception of anal fi ssures. Physical examination showed two vulvar ulcers of about 15 mm in diameter on the inside of her left labium minus. Further gynaecological examination, however, showed no abnormalities. Laboratory test results showed a white blood count of 10·1×10 cells/L, with 74% neutrophils, and a C-reactive protein concentration of 85 mg/L. Diff erential diagnosis included infectious and malignant diseases. Cervical and urethral swabs were negative for chlamydia, gonorrhoea, and syphilis. Biopsy showed tissue fragments with a striking non-specifi c granulation tissue response, in the absence of epithelium or granulomas. Immunohisto chemistry for cytomegalovirus and herpes simplex virus was negative. A dermatologist suggested she had secondary impetiginisation after an infection with herpes simplex virus, and prescribed an antibacterial ointment (fusidic acid) to be applied on the ulcers. However, this treatment had no notable eff ect and the herpes-PCR and bacterial cultures were negative. 3 weeks after the patient’s initial out-patient visit, on further questioning she said that she had had anal bleeding three times in the previous month, as well as episodes of diarrhoea. Physical examination then showed three vulvar ulcers (fi gure), and on rectal examination we found an irregular rectal mucosa, probably caused by haemorrhoids. Because of rectal bleeding and diarrhoea, an underlying gastrointestinal disease as possible cause of her vulvar ulcerations was considered. At that time her C-reactive protein had increased to 136 mg/L and weight loss had progressed to a total of 8 kg. Colonoscopy showed macroscopic features of Crohn’s disease with a cobblestone appearance of the transverse colon and a mild terminal ileitis. Colon tissue biopsies showed a ulcerative non-specifi c infl ammation with granulomas. A diagnosis of Crohn’s disease of the colon and terminal ileum with vulvar manifestations was made. The patient was treated with prednisolone (for 10 weeks), vitamin D, and calcium, resulting in full clinical remission. When last seen, in October, 2005, she remained in clinical remission without signs of vulvar abnormalities. In this patient with vulvar ulceration, a gynaecological cause was initially considered because there were no other complaints and no abnormalities on physical examination. Vulvar ulceration as the primary presentation of Crohn’s disease is rare and diffi cult to diagnose owing to the many other causes of such ulceration. Case management can be diffi cult: treatment options include corticosteroids, sulfasalazine, azathioprine, and thalidomide. This case illustrates the importance of indepth questioning—earlier detailed inquiry could have prevented the referral to the wrong type of specialist. Doctors should bear in mind that a local problem can be a manifestation of a systemic disorder.