Palmoplantar keratoderma is a thickening of the soles of feet and the palms of the hands. The thickening may be symmetrical and found in infants during their first few months of life. It may also appear as a snakeskin or have a waxy appearance in infants. Palmoplantar keratoderma may also appear as big masses of keratin similar looking as calluses. The keratin areas may be lined up on the sole or overlap each other. They may appear on pressure areas of the foot. In another form of the disorder, small lesions may appear on the soles of the feet. They can appear in groups and may be in one location on the sole instead of diffused throughout the entire sole. In some cases, the area afflicted looks like a glove or stocking has been placed on the foot, involving the sole. Cause Palmoplantar keratoderma is most likely a hereditary condition. Some of the congenital disorders that lead to its development include: • Charcot-Marie-Tooth disease • Acral keratoderma • Keratosis follicularis • Keratosis palmoplantar nummularis • Tylosis • Unna-Thost disease In some cases, repeated friction can create a worsening of the thickening of the skin on the soles of the feet in those with these genetic disorders. Palmoplantar keratoderma may also be an acquired condition, although no one knows why it occurs in those without the genetic predisposition for the condition. Treatment and Prevention Hardened areas on the sole are often treated with lotions that can soften them. Some podiatrists and medical doctors may use vitamin A or vitamin D ointments which appear to have some effectiveness, or vitamin A retinoids taken orally. Also, agents that can dissolve the hardened area – such as ones with salicylic acid may be part of the treatment. Cushioned insoles are very important for this condition. And as always, if there are any other structural abnormalities of the foot, orthotic insoles and arch supports, heel cups, heel lifts, or metatarsal pads may be indicated.