Palmoplantar keratoderma (PPK)
What is it?
“Palmoplantar” means palms of the hands and soles of the feet,and “keratoderma” means thickened skin. So palmoplantar keratoderma is a disorder in which the skin of the palms and soles is abnormally thick. It is rare, and it often runs in families. There are different types, but all members of the same family will have the same type.
What does it look like?
The palms and soles may look normal at birth, or slightly whitish. Later the affected skin becomes thickened. Sometimes it first appears when the child starts to walk, and most types become more apparent with friction and with age. The affected skin may be red and flaky, or hard and yellowish. In some types the keratoderma affects the whole surface of the palms and soles, in others it is streaky or patchy like corns (calluses). Sometimes it extends round the sides to the backs of the fingers and tops of the toes – this is called a “trangrediens” pattern.
What problems does it cause?
Palmoplantar keratoderma can cause difficulty with walking, because of pain in the feet. The thick skin and sweating of the feet makes them particularly susceptible to odour, and to fungal infection (athlete’s foot). The thick skin on the palms may reduce sensitivity in the finger tips, impairing manual dexterity. All these problems, together with the unusual appearance can be stressful and lead to psychological difficulties.