Familial Clustering of Primary Hypertrophic Osteoarthropathy (Pachydermoperiostosis): A Case Series of Five Patients

Primary hypertrophic osteoarthropathy (PHO), also known as pachydermoperiostosis (PDP), is a rare hereditary disorder characterized by digital clubbing, periostosis, pachydermia, and variable systemic manifestations1-4. Familial occurrence and genetic heterogeneity have been described, particularly involving variants in HPGD and SLCO2A1, genes related to prostaglandin E2 metabolism and transport4-7. We report five patients from familial clusters who presented with variable manifestations of PDP. Clinical findings, radiographic features, laboratory investigations, family history, treatment, and 1-year outcomes were reviewed. The age at evaluation ranged from 18 to 70 years, with male predominance. All patients had digital clubbing and radiological evidence of periostosis, while pachydermia, hyperhidrosis, arthralgia, and cutis verticis gyrata varied in severity. Secondary causes of hypertrophic osteoarthropathy, including pulmonary, cardiac, malignant, infectious, and endocrine causes, were excluded through targeted clinical assessment and investigations8-12. Management was symptomatic and included non-steroidal anti-inflammatory drugs, selective COX-2 inhibitors, corticosteroids in selected inflammatory episodes, bisphosphonate therapy in severe bone pain, physiotherapy, and supportive dermatological care11,13,19,20. Most patients achieved symptomatic improvement in pain and function, although hyperhidrosis and pachydermia persisted. This case series emphasizes the importance of recognizing familial PDP, excluding secondary hypertrophic osteoarthropathy, and providing individualized supportive treatment. Medicine Today 2026, Vol.38 (2): 336-339