Atypical Presentation of Papillon–Lefèvre Syndrome: A Case of Isolated Cutaneous Manifestations Without Dental Involvement

<b>Background and Clinical Significance:</b> Papillon-Lefèvre syndrome (PLS) is an autosomal recessive genetic skin disorder. Genetic studies have demonstrated that mutations in the Cathepsin-C (CTSC) gene, mapped to chromosome 11q14.1-q14.3, are responsible for the pathogenesis of PLS. The hallmark characteristics of this syndrome are palmoplantar keratoderma and severe periodontal disease that leads to premature tooth loss. Palmoplantar keratoderma commonly manifests during early childhood (ages one to four), followed by the onset of severe periodontitis around the age of three to four years. Although periodontitis and premature tooth loss are considered hallmark features, a limited number of cases lacking oral involvement have been reported, underscoring the phenotypic variability in PLS. <b>Case Presentation:</b> This report describes a 6-year-old female patient whose chief presenting complaint was palmoplantar keratoderma, recurrent skin infections, necrotizing granulomatous inflammation of the kidney, and delayed growth; she was genetically confirmed to have a CTSC mutation associated with PLS, yet without any dental manifestations. The lack of oral manifestations and the presence of necrotizing granulomatous inflammation of the kidney in this genetically validated case highlight an atypical presentation. <b>Conclusions:</b> This report discusses an unusual case of PLS of a patient displaying classic skin features without any dental issues.