Background. Pachydermoperiostosis (or primary hypertrophic osteoarthropathy) is a rare genetic disease that usually begins in childhood or adolescence, is characterized by certain clinical signs (pachydermia, periostosis, drum sticks) that gradually progress over many years until the disease stabilizes. Currently, there are 2 genes in which mutations are associated with the development of pachydermoperiostosis - HPGD and SLCO2A1. The functions of these genes are not fully understood, but their influence on the metabolism of prostaglandin E2 is known. Case presentation. We present a case of a 20-year-old patient mistakenly diagnosed as juvenile idiopathic arthritis. Symptoms on admission to the hospital: pain accompanied by swelling in the hands and feet, arthralgias in the talocrural joints, knees with slight swelling, paresthesia in the extremities, hyperhidrosis, fatigue. Clinical and paraclinical examinations confirmed the diagnosis of pachydermoperiostosis. Conclusions. Pachydermoperiostosis should be considered as a differential diagnosis when a patient presents with hypertrophic osteoarthropathy and acromegalic features.