Metronidazole for the treatment of cutaneous vulval Crohn disease: A systematic review

BACKGROUND: Cutaneous vulval Crohn disease (VCD) is an under‐recognised extra‐intestinal manifestation of Crohn disease (CD) which is challenging to identify and treat. It causes significant oedema, painful deep fissures, and has potential to cause permanent disfiguring changes to vulval anatomy. There is no agreement on the best management for VCD. OBJECTIVES: This systematic review evaluates the use of metronidazole for the treatment of VCD in women and children. METHODS: We conducted a systematic review (PROSPERO CRD42021285033) of the use of metronidazole in clinically or histologically diagnosed non‐contiguous VCD in patients of all ages and ethnicities. We recorded clinical improvement, reduction in flares, relapse and adverse events using a standardised form. RESULTS: 49 records (40 case reports and 9 case series) met inclusion criteria, comprising a total of 57 patients with an age range of 5–61 years. The most reported presenting features in VCD were: oedema, erythema, ulcers/fissures and induration/thickening. Gastrointestinal CD was present in 33/57 (58%). Vulval biopsies were undertaken in 47/57 (83%). Daily doses ranged from 250 to 1500 mg with treatment duration 8 days to 18 months. Improvement of any magnitude was observed in 40/57 (70%) cases. Relapse was described in 11/57 (19%) cases. No response/worsening was reported in 17/57 (30%) cases. Adverse events occurred in two patients. CONCLUSION: Metronidazole appears to be useful in managing VCD, either as a primary treatment or adjunctive therapy. However, the evidence is insufficient for firm conclusions to be drawn. Further studies including randomised controlled trials are recommended.