Pachydermoperiostosis Associated With a Rare SLCO2A1 Mutation: A Case Report and Literature Review.

Pachydermoperiostosis (PDP), also known as primary hypertrophic osteoarthropathy, is a rare genetic disorder characterized by digital clubbing, periostosis, and pachydermia. It typically presents during adolescence or early adulthood and is commonly associated with mutations in the HPGD or SLCO2A1 genes. Due to its nonspecific clinical features, PDP is often misdiagnosed, resulting in delayed treatment. We report the case of a 26-year-old Arab male with an eight-year history of progressive facial skin thickening, hyperhidrosis, and digital clubbing. Laboratory investigations were unremarkable, while imaging revealed periostosis. Genetic analysis identified a SLCO2A1 mutation (c.563A>G, p.Gln188Arg). Our patient experienced significant physical discomfort and psychological distress, with notable improvement following treatment with nonsteroidal anti-inflammatory drugs and corticosteroids. In our review of 246 PDP cases with SLCO2A1 mutations, the c.940+1G>A splice variant was most frequent. PDP shows marked male predominance (92.3%) and is most prevalent in Asian populations, particularly Chinese (53.3%). Most diagnoses occurred between ages ≤25 and 25-45 years. Common manifestations include digital clubbing (82.5%), pachydermia (74.4%), and hyperhidrosis (41.1%), with consanguinity reported in 29.7% of cases. Clinical overlap with rheumatologic and endocrine disorders often delays diagnosis. Genetic confirmation is essential for accurate identification. This case reinforces the importance of considering PDP in patients with unexplained digital clubbing and pachydermia. Early recognition and genetic confirmation of PDP can prevent unnecessary testing and guide effective treatment. Comprehensive, multidisciplinary care, including psychosocial support, is vital to optimize outcomes in this rare genetic disorder.