Azathioprine is effective for oral involvement in Crohn's disease but not for orofacial granulomatosis alone

Background There have been no previous reports assessing the effectiveness of azathioprine (AZA) in the treatment of orofacial granulomatosis (OFG). This report is a review of patients receiving AZA for active OFG with or without concomitant gut Crohn's disease (CD) in a specialist tertiary referral centre. Methods Clinical response was defined by Global Physician Assessment at 4-, 12- and 24-month follow-up and a standardised oral disease activity score (ODAS). Results Sixty of 215 patients seen with OFG in our clinic over a 12-year period were treated with AZA. Of these, 22 had concomitant CD. The proportion of patients responding to AZA with a diagnosis of CD/OFG vs. OFG only at 4, 12 and 24 months were 54% vs. 21% (P = 0.03), 59% vs. 21% (P = 0.003) and 41% vs. 24% (P = 0.16), respectively. A statistically significant difference was seen between starting and follow-up ODAS scores at 4 months in the CD/OFG group which was not observed in the OFG only group. Factors predicting a need for AZA included a diagnosis of intestinal CD, sulcal swelling, sulcal ulcers and upper lip involvement. The factor predicting response to treatment was a diagnosis of CD at 12 months of follow-up. No difference in the number of adverse effects was observed between the two groups of patients. Conclusions AZA is significantly more effective in the treatment of oral disease with a concurrent diagnosis of CD rather than in the treatment of OFG alone.