The Diagnostic Utility of Lip Biopsy in Paediatric Crohn's Disease: A 10-year Single-centre Retrospective Study

Oral manifestations of paediatric Crohn's disease (CD) are reported in up to 60% of cases. Lip biopsy can be used to histologically diagnose oral CD. We evaluated the utility of lip biopsy in children under initial investigation for potential CD. A 10-year retrospective review of electronic patient records at a single tertiary paediatric surgery centre was performed. All patients aged ≤16 years who underwent lip biopsy were included. Clinical features, histology, and diagnostic details were extracted. Forty-two children underwent lip biopsy. Median age at biopsy was 13.3 years (11.0-14.9). Final diagnosis was CD in 21/42 (50%) children, indeterminant colitis in 3/42 (7%), orofacial granulomatosis (OFG) in 3/42 (7%), coeliac disease in 1/42 (2%), and eosinophilic oesophagitis in 1/42 (2%). Thirteen children (31%) received no formal diagnosis. The most common symptoms reported were oral ulceration (33/42, 79%), lip swelling (21/42, 50%), and abdominal pain (19/42, 45%). Lip biopsy histology was normal in 11/42 (26%). In 24/42 (57%), non-granulomatous inflammation was seen. In 7/42 (17%) lip biopsy identified granulomatous inflammation: three (7%) had endoscopic biopsies concordant for CD, three (7%) had negative endoscopic biopsies but were diagnosed with CD, and one was diagnosed with OFG (2%). Sensitivity was 29% and specificity was 95%. Lip biopsy has low sensitivity but high specificity for diagnosing CD. Lip biopsy diagnosed CD in 7% when endoscopic biopsies were negative, enabling treatment. LB is a useful diagnostic test for CD in children presenting with oral symptoms. III.