Oral lesions preceding paediatric perianal fistulising Crohn's disease

A 14-year-old girl with refractory oral aphthae and gingival swelling for 6 months (Fig. 1a, b) was referred to our institution. The patient had unremarkable family and medical histories. A biopsy was performed on the oral lesion. Histopathological examination showed fissured ulcers with neutrophil, plasma cell and lymphocyte infiltration. These ulcers were diagnosed as chronic inflammation with a suspicious origin (Fig. S1a, b). Subsequently, her oral symptoms repeated a cycle of remission and worsening. During these 2 years, dexamethasone ointment and oral ascorbic acid were administered, but neither was effective. After 2 years, she presented with fever, left buttock tenderness and pus drainage from the anus. Colonoscopy revealed small bumps with ulcers and adherent purulent mucus in the rectum (Fig. 1c). Histopathological examination revealed inflammatory cell infiltration and non-caseating epithelioid cell granuloma in the lamina propria (Fig. S1c, d). No abnormal findings were noted from the ileum to the sigmoid colon. Magnetic resonance imaging revealed a perianal fistula in the left buttock (Fig. 1d). Esophagogastroduodenoscopy revealed a bamboo-joint-like appearance in the gastric region. Capsule enteroscopy revealed no abnormal findings in the small bowel. She was diagnosed with perianal fistulising Crohn's disease and managed with infliximab. Though her oral symptoms and perianal lesions improved, perianal lesions recurred after gingivitis, and numerous aphthae were observed. Oral lesions are often observed in patients with inflammatory bowel disease (IBD), particularly paediatric patients with Crohn's disease.1 This combination often presents as aphthae with longitudinal presentation or skip lesions separated by normal-appearing mucosa buccally or labially. A higher incidence of gingivitis and periodontitis has been observed among patients with IBD.2 The detection of oral lesions may precede the diagnosis of IBD.3 Oral lesions are considered to be parallel to intestinal disease activity and are associated with perianal disease.4 In our study, the perianal lesions worsened following the recurrence of the oral lesions. Paediatricians should recognise that oral symptoms may be an initial manifestation of IBD. Figure S1. Histopathological findings. (a) Mucosal biopsy of the oral cavity reveals longitudinal ulcers; (b) Inflammatory granulation tissue at the base of the ulcer infiltrated with numerous neutrophils, plasma cells, and lymphocytes; (c) Mucosal biopsy of the rectum: severe mixed inflammatory cell infiltration (d) Non-caseating epithelioid cell granuloma in the lamina propria. Original magnification: A, ×40; B, ×400; C, ×100; and D, ×400. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.