Pachonychia congenita (PC) is a rare inherited condition that causes abnormal, thickened growth of the nails and often thickening of the skin of the feet. It affects about 5 – 10,000 people worldwide.
It is caused by a defect in a keratin gene which makes a protein that is present in the skin of the hands and feet. As a result, the normal loss of the skin in this area is interrupted and people get excess hard skin forming. The nails on the hands and feet get thick and brittle and there is thickening of the soles of the feet. Sometimes, people find they sweat too much too.
People affected by Pachonychia congenita tend to start noticing this in childhood. Clues to it coming on are certain things like having teeth at birth.
Thickened skin on the feet can cause pain and difficulty in walking. Nail problems cause difficulties in grip and holding things with finger tips.
Treatment is aimed at relieving the symptoms. Salicylic acid and urea creams can be used to break down and soften thickened skin. Retinoid tablets can be used to reduce the formation of excess skin.