A Case of Pachydermodactyly

Abstract

A 42-year-old male had been aware of asymptomatic swelling of the PIP joints on the dorsal aspect of both hands since childhood. As it did not interfere with his daily life, he did not seek treatment. A few years before his initial visit to our department, he began to experience morning stiffness. On examination, swelling and scaling of the lateral skin of the PIP joints of the second to fourth ngers on both hands were observed. However, there was no pain or limitation of joint range of motion. Radiographic examination revealed soft tissue swelling without any bony lesions. Blood tests were negative for antinuclear antibodies, rheumatoid factor, and other autoantibodies. Histopathological examination of the skin biopsy from the swollen area showed epidermal thickening and hyperkeratosis. Based on these ndings, the patient was diagnosed with pachydermodactyly. Pachydermodactyly can be diagnosed clinically without the need for skin biopsy or MRI. Previous reports have suggested an association with mechanical stimulation, but no specic habits were identied in our case. Although the absence of morning stiffness is considered a characteristic feature of pachydermodactyly, our patient reported experiencing morning stiffness. We hypothesize that the limited number of reported cases of morning stiffness may be due to misdiagnosis,particularly in cases where differentiation from inammatory joint diseases is challenging. Pachydermodactyly is a benign condition that can be easily misdiagnosed. Increased awareness of this condition may help avoid unnecessary investigations and treatments. Skin Research, 23 : 211-216, 2024