two types, primary type is a condition chiefly characterized by thickening of the skin of the head and distal extremities, deep folds and furrows of the skin of the forehead, cheeks, and scalp, seborrhea, hyperhidrosis, periostosis of the long bones, digital clubbing, and spadelike enlargement of the hands and feet, it is more prevalent in the male; secondary type is a condition with symmetrical osteitis of the four limbs, chiefly localized to the phalanges and the terminal epiphyses of the long bones of the forearm and leg, sometimes extending to the proximal ends of the limbs and the flat bones, and accompanied by dorsal kyphosis and joint involvement, and is often secondary to chronic conditions of the lungs and heart.