Background: Genital lymphoedema is caused by inflammation and granuloma formation in the lymphatic system and is recognised as a presentation of cutaneous metastatic Crohn's disease (CD). It can precede luminal presentation by months to years, particularly in younger patients; many children with cutaneous CD have genital involvement. Despite several case reports, there is a scarcity of epidemiological studies demonstrating the incidence of genital lymphoedema in a paediatric population with Crohn's disease. We aimed to identify the incidence of genital lymphoedema as the initial presentation of paediatric CD within a population-based cohort.
Methods: Using a prospective regional database demographics and phenotypic data of all incident and prevalent paediatric inflammatory bowel disease (PIBD) patients in South-East Scotland between 01.08.97 and 31.12.11 were reviewed. Case notes of all CD patients were reviewed and those with genital involvement identified. Using all CD as the denominator, the incidence of genital lymphoedema as the initial presentation of CD in all patients (incident and prevalent) in this cohort was calculated.
Results: A total of 204 incident and prevalent cases of CD diagnosed less than 17 years of age were recorded in SES during the study period. 5 patients (2.5%) were identified as having genital involvement prior to, or at the time of, CD diagnosis. These patients were aged 4–15 years at presentation (median 9 years); 3 were male. One patient was diagnosed with CD despite normal endoscopic examination after developing perianal abscesses and fissures one year after histologically proven granulomatous genital oedema. Of the other 4 patients, only one presented with concomitant gastrointestinal and genital disease. The other patients were diagnosed with CD on endoscopy 8 months, 1 year and 3 years after initial presentation with genital oedema. 4 patients with genital oedema had concurrent perianal disease and one had oral disease.
Conclusions: To our knowledge, this is the first paediatric population-based study of genital lymphoedema as an initial presentation of CD. In this cohort, 2.5% of paediatric CD within a regional PIBD cohort at diagnosis had prior or concurrent genital lymphoedema due to CD. This significant proportion highlights the importance of considering CD as one of the many differential diagnoses of genital oedema, particularly in the presence of perianal disease or other gastrointestinal symptoms.