Pachydermoperiostosis is a disease characterized by certain changes in the skin and bones that closely resemble pulmonary hypertrophic osteoarthropathy. In pachydermoperiostosis, however, no causative factors such as pulmonary, cardiac, or hepatic disorders have been demonstrated.The disease was first described in two young brothers by Friedreich in 1868. Some 60 cases have been reported since, mostly in the French literature, but the disease was established as a clinical entity only within the last twenty years (Vague, 1948(Vague, , 1950Findlay and Oosthuizen, 1951 ;Angel, 1957).
Clinical FeaturesMales are predominantly affected and changes usually set in shortly after puberty. The disease often occurs in brothers; all these patients appear to be infertile.Skin Changes.-Thickening of the skin occurs over the face, forehead, scalp, hands, and feet. The face is drawn into thick folds, giving it a creased appearance. The most prominent of these folds are on the forehead, cheeks, and nasolabial folds, a condition known as cutis verticis gyrata. The eyelids are often thickened. The skin is greasy and may show changes due to acne. Histological examination of the skin shows increased thickness of the epidermis, with hypoplasia of the sweat and sebaceous glands and histiocytic infiltration of the corium.Bone Chatiges.-The bones, especially those of the distal parts of the limbs, are broadened without being increased in length. This may give rise to marked ,thickening of the wrists, lower parts of the legs, and ankles, as well as to increased size of hands and feet. The nails may be thickened and curved, with severe clubbing of the fingers and toes. Effusions into the knees and ankles, which may produce pronounced swelling of these joints, are often present. A bone biopsy by Leinwand and Duryee (1943) showed foci of plasma cells in the paraperiosteal tissues. Radiological studies show cortical thickening and irregular cortical outgrowths due to deposition of periosteal new bone on the diaphyses of long bones, particularly of the more distal parts. It is very rare for the carpus, tarsus, vertebrae, or skull to be involved. No changes occur in the articular surfaces.Syinptoms.-Patients complain chiefly of heavy perspiration over the hands and feet and sometimes over the face, clumsiness in the use of the extremities, and pain in the limbs, especially when joints are involved.Course and Prognosis.-These abnormal processes usually progress slowly and painlessly for several years. Lasting and natural arrest may then occur, but after a