CheckAP: Prevalence of psoriatic arthritis (PsA) and performance evaluation of the EARP questionnaire in the population of Portuguese patients with psoriasis followed in a dermatology setting.

Background: The percentage of Portuguese psoriasis patients with psoriatic arthritis is unknown but musculoskeletal complaints related to PsA affect up to a third of patients. Dermatologists can identify early PsA as skin symptoms often precede joint symptoms in 80% of patients. Efficient and easy to perform screening tools are needed to help dermatologists effectively discriminate between Pso and PsA patients.

Pachyonychia congenita type 2 (Jackson-Lawler syndrome) or PC-17: case report.

Pachyonychia congenita (PC) is a rare genodermatosis caused by mutations in any of the four genes KRT6A, KRT6B, KRT16, or KRT17, which can lead to dystrophic, thickened nails and focal palmoplantar keratoderma, among other manifestations. Although classically subdivided into two major variants, PC-1 (Jadassohn-Lewandowski syndrome) and PC-2 (Jackson-Lawler syndrome), according to the localization of the mutations in the KRT6A/KRT16 or KRT6B/KRT17 genes, respectively, a classification system based on the mutant gene (PC-6a, PC-6b, PC-16 and PC-17) has been recently proposed. We report a 2-year-old female patient with a history of thickened and discolored nails, small cystic papulonodules on the central face, dry, unruly and curly hair, slight palmoplantar hyperkeratosis, and natal teeth.