This is a rare inherited skin and nail condition characterized by the abnormality of the nails, the development of painful blisters and calluses on the soles of the feet and the palms of the hands. This condition does not affect the lifespan of the individual but most of them can experience constant pain. The severe blisters and calluses on the feet can almost make it impossible for them to walk. The symptoms of the condition can become evident within the first few months of the infant’s life. There are two types of this disease; type 1 and type 2 that are distinguished based on the genetic cause and the symptoms.
Causes
Genetic mutations in a number of genes have been identified to cause this disease including KRT6A, KRT6B, KRT6C, KRT16 and KRT17. These genes are important for the production of proteins called keratins that provide support to skin cells, give them their shape and strength. The genetic mutation results in the structure of the keratin proteins that are altered thus preventing them from developing stable networks within the cells. Hence the skin cells become very fragile and are easily damaged even by minor trauma. When these individuals carry out the normal activities such as walking, the skin cells can break down resulting in the development of painful blisters and calluses. The problem with the keratins can also affect the growth of the cells in the hair follicles and the nails. This disease is considered to be inherited in an autosomal dominant pattern meaning a single copy of the defective gene in each cell can cause the condition. Some cases can also develop because of a new mutation with no history of its prevalence in the family.
Symptoms
The symptoms can vary greatly among the affected cases. The blisters can develop under the calluses that can cause extreme pain. As the result, the affected individual may require the use of crutches or wheelchairs. The problem of the fingernails can become evident within the first few months or years of the infant’s life which can become thick and abnormally shaped. In some of the cases, the infection can also develop under the nails which can be painful. Additional features can include white patches inside the mouth, bumps that can occur around hair follicles on the knees, elbows and waistline, along with the growth of cysts in the groin, armpits or the scalp. Some of the affected infants may have natal teeth that are present at the birth. Rarely, it can affect the voice box called larynx presenting symptoms such as hoarseness and breathing problems.
Diagnosis
A skin biopsy can help detect the condition. The molecular genetic testing can identify the mutation responsible for the development of the disease.
Treatment
There is no cure for the disease and the symptoms can be managed at home or with the help of a professional. The use of optical agents such as salicylic acid and moisturizers can help soften the skin in some case. In addition, the thickened nails require to be trimmed regularly, pain medications can be beneficial and bleach baths can help reduce infection.
References
https://www.dermnetnz.org/topics/pachyonychia-congenita/
https://ghr.nlm.nih.gov/condition/pachyonychia-congenita#inheritance
https://rarediseases.org/rare-diseases/pachyonychia-congenita/
http://www.pachyonychia.org/what-is-pc/
