Epidermolytic palmoplantar keratoderma Vorner type

Epidermolytic Palmoplantar Keratoderma of Vorner Type (EPPK), also known as Vorner's Epidermolytic Palmoplantar Keratoderma, is a rare genetic skin disorder characterized by thickening (keratoderma) of the skin on the palms of the hands and soles of the feet. This condition falls under the broader category of palmoplantar keratodermas (PPK), which are disorders affecting the palms and soles with varying degrees of severity and genetic causes. EPPK specifically is inherited in an autosomal dominant manner and is caused by mutations in the KRT9 gene on chromosome 17q21 or, less commonly, the KRT1 gene.

Symptoms and Diagnosis

The hallmark of EPPK is the development of thick, rough, and sometimes scaly skin on the palms and soles. This condition typically presents at birth or in early childhood. The severity can vary significantly among affected individuals, even within the same family. In some cases, the keratoderma may extend to the sides of the hands and feet and may be associated with painful fissures, redness, and itching.

Diagnosis of EPPK is primarily clinical, based on the characteristic appearance of the skin. However, genetic testing can confirm the diagnosis by identifying mutations in the KRT9 or KRT1 genes. Histopathological examination of a skin biopsy may also aid in diagnosis, showing features of epidermolytic hyperkeratosis, which is a distinctive pattern of skin changes under the microscope.

Treatment

There is no cure for EPPK, and treatment focuses on managing symptoms and preventing complications. Emollients and keratolytic agents (such as salicylic acid or urea-based creams) can help soften the thickened skin and reduce discomfort. In severe cases, systemic treatments, including retinoids, may be considered to reduce keratin production. Regular follow-up with a dermatologist is recommended to monitor the condition and adjust treatment as necessary.

Genetics

EPPK is caused by mutations in the KRT9 gene in most cases, which encodes for keratin 9, a protein that is essential for the structural integrity of the epidermis in the palms and soles. Mutations in the KRT1 gene, which encodes keratin 1, have also been associated with this condition but are less common. The disorder is inherited in an autosomal dominant pattern, meaning a single copy of the altered gene in each cell is sufficient to cause the disorder. There is a 50% chance of passing the mutated gene to offspring.

Epidemiology

EPPK is a rare condition, though its exact prevalence is unknown. It affects males and females equally and has been reported in various ethnic groups worldwide.

See Also

• Palmoplantar Keratoderma
• Keratin
• Genetic Disorders
• Skin Diseases