The term palmoplantar keratoderma describes a diverse group of skin conditions affecting the hands and feet—specifically the palms and the soles (also known as the plantar region of the foot, hence the name “palmo-plantar keratoderma”).
Keratoderma means “thickened skin.” Affected individuals suffer calluses and blisters so painful that they experience difficulty walking. Most varieties of this condition are congenital—and usually inherited—although there are acquired forms as well.
All varieties of palmoplantar keratoderma can affect both the hands and the feet, but focal palmoplantar keratoderma tends mostly to affect the skin on the bottom of the foot.
Symptoms of Palmoplantar Keratoderma That Develop
People who suffer from this condition have abnormally thick skin on the soles of their feet and palms of their hands. This thickening of the skin begins to develop in early childhood, usually around the time the affected child learns how to walk.
The affected skin acquires a reddish, flaky appearance and eventually hardens into thick, yellowish pads of callus. Depending on which type of keratoderma the person suffers from, it can affect the entire sole of the foot or it may appear in streaks or patches, possibly mimicking the appearance of corns.
There is also an extremely rare genetic mutation that causes a combination of disorders known as palmoplantar keratoderma with deafness.
Children affected by this condition develop hearing loss, particularly for high-pitched sounds, at around the same time the skin on their soles and palms begins to thicken. Fortunately, this genetic condition is rare, and has only been identified in ten families.
What Are The Complications Of Palmoplantar Keratoderma?
The pain caused by the blisters and calluses can make walking difficult, and the feet are prone to excessive sweating, which causes foot odor and makes them susceptible to athlete’s foot and other types of fungal infections of the skin. In rare cases, abnormalities of the toenails may develop. The combination of these difficulties with the aesthetically undesirable appearance of the feet can lead to psychological and emotional problems, particularly in children.
Why Did I Develop Palmoplantar Keratoderma?
In general, the cause of this condition is abnormal genes that cause the body to incorrectly manufacture certain keratin proteins necessary for strong, resilient skin, hair, and nail tissue.
These proteins fail to form networks within the skin cells, making those cells fragile. These easily damaged cells are less resistant to the minor trauma that results from the ordinary friction that occurs when we stand or walk.
There are three general classifications of palmoplantar keratoderma:
- Focal: With this condition, the keratoderma appears at pressure points, i.e., areas of the feet that bear significant weight or that are subject to friction when we walk.
- Diffuse: Also known as Vorner’s disease, this condition tends to result in a uniform pattern of keratoderma across the skin of the soles and palms.
- Punctate: With this form of palmoplantar keratoderma, numerous small nodules appear all over the soles. This condition tends to cause more pain in weight-bearing parts of the foot.
Acquired Palmoplantar Keratoderma
While palmoplantar keratoderma is in most cases a genetic condition, there are situations in which it can be acquired, usually as a symptom of some inflammatory skin condition, such as psoriasis, eczema, ichthyosis, scabies, or dermatitis.
The Diagnosis, Treatment, and Prognosis Of Palmoplantar Keratoderma
Diagnosis of palmoplantar keratoderma will usually be made by the age of two or three. Treatment options, unfortunately, are somewhat limited.
The problem is that nothing can be done about the patient’s genetic programming, so the faulty proteins that lead to the calluses, blisters, and thickened skin will continue to appear.
Debridement of the skin—for example, if an individual attempts to deal with the problem without medical intervention by getting a pedicure—may in some cases make the problem worse.
While the problem cannot be cured, the symptoms can generally be mitigated, although affected individuals can expect to have to manage their condition throughout their lives.
Prescription or over-the-counter antifungal creams may help with foot odor and other symptoms of fungal infection, and regular application of moisturizing creams can slow the formation of calluses.
Custom-made insoles can be designed for the patient’s shoes to relieve some of the pressure on weight-bearing parts of the foot. In rare cases a doctor might prescribe a drug known as acitretin, which thins the affected skin.