What is Darier Disease?
Darier Disease which is also known by the name of Keratosis Follicularis is an extremely rare genetic pathological condition of the skin. Darier Disease is characterized by presence of skin lesions which can be in the shape of thick bumps with irregular circumference. They tend to be greasy and have a yellowish crust. The lesions become hard as the condition progresses and with time tend to increase in size and spread.
The nails and the mucous membranes are the areas that are most affected by the lesions caused by Darier Disease. This is a condition which for some time may go into remission only to recur again with more intensity. This condition follows an autosomal dominant pattern of inheritance meaning that only one copy of the defective gene from any parent is enough for a child to get Darier Disease.
What are the Causes of Darier Disease?
Darier Disease normally tends to occur due to spontaneous mutation in genes or de novo mutations, although in some cases it follows an autosomal dominant pattern of inheritance.
The gene responsible for development of Darier Disease is the ATP2A2 gene which is located in the long arm of chromosome 12. The function of the ATP2A2 gene is to produce a protein that regulates calcium in the cells.
This protein is called as SERCA2 and functions as a carrier of calcium ions from the cytoplasm in the cell to the endoplasmic reticulum where the proteins are processed. A malfunction in this process results in the development of Darier Disease.
What are the Symptoms of Darier Disease?
The presenting features of Darier Disease begin during the teenage years of an individual at around puberty. At times, there may be symptoms experienced in older individuals as well but they are extremely rare.
The severity and the extent of this condition is significantly variable in that while some youngsters may have very less lesions whereas others may have an abundance of lesions caused by Darier Disease.
The characteristics of the lesions caused by Darier Disease is that they tend to be small, greasy, have an irregular circumference, and are yellowish in color. The areas usually affected by these lesions are areas which are in close proximity to the sebaceous glands to include the chest, back, scalp, and the forehead.
These lesions start to become thick as the disease progresses and assume a brownish color to it. They also become scaly and dark. Over time, the size of the lesions starts to increase and eventually all these lesions join together to form big large plaques which may at times cover the entire body.
These lesions are extremely itchy and the affected individual may have persistent sense of itchiness around the affected area. As a result of regular scratching around the affected area, the lesions may become scraped or bruised which may give rise to bacterial and fungal infections which may further complicate the picture.
If the individual gets infected by the herpes simplex virus then the individual may also find the lesions extremely painful. Heat and exercise also tends to worsen the symptoms caused by Darier Disease.
Another common symptom that is noticed in people with Darier Disease is the presence of yellowish papules behind the hands and feet. This is in fact the place where the symptoms of Darier Disease start.
Nails are yet another area which are most affected by Darier Disease. The nails in affected individuals tend to be split and extremely fragile. Additionally, the mucous membranes of the mouth are also the most affected area in Darier Disease.
The lesions tend to develop in the roof of the mouth along with the gums. Internally, the lesions may develop in the larynx and the esophagus. The salivary gland may be significantly affected as a result of Darier Disease.
How is Darier Disease Diagnosed?
A thorough evaluation of the affected individual with a detailed examination of the lesions may show up the characteristic features of Darier Disease. Additionally, the patient's history is also beneficial in establishing a diagnosis of Darier Disease.
A skin tissue biopsy may also be done to confirm the diagnosis of Darier Disease. The biopsy will reveal abnormal formation of keratin which is a primary finding of this condition and virtually confirms the diagnosis of Darier Disease.
How is Darier Disease Treated?
The treatment for Darier Disease is basically symptomatic and hence is variable depending on the severity and the extent of the symptoms. For some individuals, the physician may recommend sunscreens, loose clothing, moistures and exposure to heat and excessive sunlight to help with the symptoms of Darier Disease.
In some cases, retinoids applied directly to the lesions may help reduce the thickness of the lesions caused by Darier Disease. Salicylic acid is also quite beneficial in treatment of Darier Disease.
Topical steroids for some time may also be quite beneficial in treating the lesions of Darier Disease. The most preferred retinoids taken for treatment of Darier Disease are tretinoin acitretin, although there may be some side effects associated with this and hence individuals are recommended to weigh the side effect profile against the benefits before embarking on this medication.
For females, it is highly recommended that if they are on retinoids that they avoid getting pregnant as it may result in complications. In cases of infections caused by the lesions of Darier Disease, antibiotics may be given to treat those.
For cases of herpes simplex virus, medications like Acyclovir is the most preferred medication to treat the infection caused as a result of Darier Disease.