Clinical course of paediatric-onset Behcet's disease in young adulthood.

OBJECTIVES: Although Behcet's disease (BD) typically manifests in the second or third decade of life, initial symptoms may appear at a younger age. It may also take a longer time for the full disease phenotype to develop after the first symptom onset in paediatric patients. In this study, the objective was to assess the clinical course of paediatric-onset BD in young adult period. METHODS: The files of 112 patients diagnosed with BD before the age of 18, selected from five tertiary clinics, were retrospectively examined. Patients with a follow-up of less than 6 months were excluded. RESULTS: The study comprised 93 patients with paediatric-onset BD, of whom 64.5% (n = 60) were male. The median age of diagnosis was 15 years (13-17). Major organ involvement was present in 49 (52.5%) patients. The most commonly affected organ was the eye (29%). Sixty-eight patients (73.1%) had follow-up data in adulthood. Forty patients had only mucocutaneous manifestations in the paediatric period. During follow-up in adulthood, 15 (53.3% were male) had new major organ involvement, at a mean of 10.1 (s.d.: 7.9) years after diagnosis. Twenty-eight patients (41.1%) experienced major organ involvement during the paediatric period. In follow-up during adulthood, 12 (42.8%) developed new major organ involvement and/or relapse of the same organ. Eighteen (26.5%) of 68 paediatric-onset BD patients had new major organ involvement, and 9 (13.2%) had a relapse during follow-up in adulthood. CONCLUSION: Our results showed that nearly one-third of paediatric BD patients have a new major organ involvement or a relapse in adulthood. Regular follow-up of paediatric BD patients in adulthood is essential for preventing long-term damage in this disease subset.