Pachydermoperiostosis (PDP) is a rare, heritable disorder that affects skin, skin derivatives (hair and sebaceous glands), and skeletal tissues. Originally described in 1868, the syndrome was more thoroughly delineated in 1935.
A hereditary form of osteoarthropathy of unknown origin marked by thickening of the skin over the face and extremities. If associated with an underlying disease, treatment of the disease may cause the symptoms and signs of this condition to disappear.