Orofacial granulomatosis (OFG) is an idiopathic inflammatory disorder of children and young adults whose clinical symptoms include swelling of the lips or face, mucosal nodularity (cobblestoning), mucosal tags, hyperplasia of the gingivae, and aphthous oral ulcers. Whether some OFG patients with clinical and histological characteristics resembling Crohn's disease (CD) are a special group (oral CD) or true CD patients with symptoms reaching all the way to the oral mucosa remains to be determined. In this study oral biopsies from 10 patients with OFG were analyzed for the presence of T cells, T-cell subsets, B cells, and macrophages, as well as cytokines (IL-4, IL-10, IFN-gamma, IL-12, and TNF-alpha), chemokines (RANTES and MIP-1alpha), and chemokine receptors (CCR3, CCR5, and CXCR3). For comparison, oral tissues from 7 patients with other granulomatous diseases were included. Compared with the non-OFG group, the OFG group had raised levels of CD4(+) T cells, IFN-gamma, IL-10, and RANTES but reduced levels of CD68(+) macrophages outside the granulomas, whereas within the granulomas the levels of CD3(+) and CD4(+) T cells and of IFN-gamma were raised, but the levels of IL-4 were decreased. These data are indicative of a Th1 environment within the oral OFG tissues, which resembles that already observed in gut CD tissues. Therefore, it can be concluded that some OFG patients have both histopathological and immunopathological features that resemble those observed in CD patients.