This is the condition characterized by the thickening of the skin that occurs on the palms of the hands and soles of the feet. This disorder can either be inherited, acquired or can develop as a feature of other underlying disorders. The acquired form of this condition can develop from changes in the individual’s health whereas the inherited form develops as the result of genetic mutation.
Causes
The inherited form of this condition develops as the result of the abnormality in the skin protein known as keratin. There are various genes identified to cause this condition and the inheritance pattern depends on the type of the gene affected. The autosomal dominant inheritance pattern involves a mutation in only one copy of the responsible gene which can cause this condition. This can occur among individuals with an affected parent or can develop for the first time with no history of this condition in the family. The autosomal recessive pattern of inheritance involves both the copies of the responsible gene in each cell that has the mutation. The acquired form can develop as the result of various skin and internal conditions such as circulation problems, infections, medications, non-cancerous internal disease and inflammatory skin condition.
Symptoms
The inherited form is divided into four different groups; diffuse, focal, punctate and transgradient. The diffuse PPK develops on the entire palm or the sole of the feet which may be thickened, hard and yellow in color. The focal PKK occurs only on the pressure or the friction points. The puncture PKK appears as the tiny skin spots on the palms of the hands and the soles of the feet. The transgradient PKK is a rare form that affects the back, hands or the feet.
Diagnosis
The diagnosis of PKK is based on the valuation of the individual’s medical history, family history, clinical examination and with various tests. The diagnosis is also based on the identification of the features of this condition and to assess if other parts of the skin such as the teeth, organs and the nails are also involved. The family history of this condition requires to be evaluated to identify the inheritance pattern and to determine whether it is acquired of inherited. A sample of the affected skin needs to be observed under the microscope that can show features characteristic of the subtype of this condition. In the severe cases, the affected individual may also be referred to the geneticist for further testing.
Treatment
The inherited form of this disorder cannot be cured although the treatment can control the symptoms. This focuses on reducing the thickness of the skin and to soften the affected areas. In several of the cases, the treatment usually provides short-term relief but presents unwanted side-effects. The treatment for the acquired form of this disorder is based on treating the underlying condition such as the infection and the tumor. The treatment of PKK can include topical retinoids, systemic retinoids, salt water soaks, removing the layers of the skin, skin grafting and topical vitamin D ointment.
References
https://rarediseases.info.nih.gov/diseases/8167/palmoplantar-keratoderma
http://www.dermnetnz.org/topics/palmoplantar-keratoderma/
http://www.firstskinfoundation.org/types-of-ichthyosis/palmoplantar-keratodermas
https://www.dermcoll.edu.au/atoz/palmoplantar-keratoderma/
