Langerhans cell histiocytosis oral lesions in pediatric patients.

Langerhans cell histiocytosis (LCH) is a disease with unknown etiology. It presents as single-system (affecting a single organ or tissue) or as multisystem (with or without risk organ involvement). The oral cavity may be involved or be the site of the first manifestation. Aim: To describe, group, and determine the frequency of oral lesions in pediatric patients with LCH, and to relate these lesions to age and the different disease subtypes. Materials and Method: Clinical and radiographic examinations were used to evaluate 95 patients diagnosed with LCH, aged 0 to 16 years, who were referred to the Department of Comprehensive Pediatric Dentistry at the School of Dentistry, University of Buenos Aires. Clinical histories were prepared and informed consents obtained. Lesions were diagnosed by observation, palpation and biopsies, and grouped according to affected tissues into bone, mucosal, and bone-mucosal. Results: 42.1% presented oral lesions, and in 14.73%, these lesions were the first manifestation of LCH. Ninety percent presented only bone lesions, while the remaining 10% presented bone-mucosal and mucosal lesions. In the single-system subtype, 52.5% presented bone lesions. In the multisystem subtypes (with or without risk organs), all three types of lesions were found. The association between age at which LCH was diagnosed and oral tissue involvement showed that bone-mucosal lesions occur in young children (average age 1.4 years) diagnosed with multisystem LCH. Oral mucosa was only affected in reactivations of the disease. Conclusions: A high frequency of oral lesions was observed, which were sometimes the first manifestation of the disease, most often affecting bone tissue. Dentists can play an active role in the initial diagnosis of the disease.