Author: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand,1999.
Exfoliative keratolysis is a common skin condition in which there is focal peeling of the palms and less often the soles. It is also known as ‘keratolysis exfoliativa’, dyshidrosis lamellosa sicca, and ‘focalpalmar peeling’.
Exfoliative keratolysis is more common during the summer months in about 50% of affected individuals, and most often affects young adults. It may be more common in those with with sweaty palms, i.e. lcoalised hyperhidrosis.
The first sign is one or more superficial air-filled blisters on the fingers or palms. The blisters burst to leave expanding collarettes of scale and circular or oval, tender, peeled areas. These peeled areas lack a normal barrier function and may become red, dry and cracked. However, they are not generally itchy.
Sometimes on the ends of the fingers the split in the skin is deeper, in which case the skin feels hard and numb and takes longer to peel off.
What is the cause of exfoliative keratolysis?
The cause of exfoliative keratolysis is unknown. Microscopy reveals cleavage within the outside horny layer of skin, the stratum corneum. It is thought that for some reason the coneocytes separate from each other prematurely. No genetic abnormality has been detected to date.
The symptoms are aggravated by exposure to irritants including water, soap, detergents and solvents. Eventually normal skin forms, but frequently exfoliative keratolysis recurs within a few weeks.
Exfoliative keratolysis is not eczema, but some cases may lead to or be confused with pompholyx, an itchy form of eczema in which there are small fluid-filled blisters.
It can also be confused with psoriasis, in which there are scaly patches, localisedepidermolysis bullosa, in which blistering occurs, or with tinea, but scrapings for fungal culture are negative.