What is Darier disease?
It is a rare inherited skin condition and is characterized by a change in the way skin cells (keratinocytes) stick together within the upper layer of the skin (epidermis).
This condition leads to changes in the skin and nails, and inside the mouth can sometimes be affected. Other names for Darier disease include Darier-White disease and Keratosis Follicularis.
What causes Darier disease?
The movement of calcium within cells is disrupted, leading to a change in the way skin cells are held together. Usually, these cells are held together like bricks cemented in a wall.
In Darier disease, the ‘cement’ that holds the skin cells together is weakened, so the cells separate easily and do not form a sound barrier against the outside world.
This condition causes the skin to become easily irritated, inflamed, and it may begin to weep. It is not due to an allergy, and it is not contagious (catching).
Darier disease is often aggravated by heat, sunlight, skin friction, excessive sweating, and it can make the skin more prone to infection. Some females may notice their skin flares before their period. Certain prescribed medications (usually taken by mouth) may also make the rash worse.
Is it hereditary?
Yes. So it can run in the family.
What are the symptoms of Darier disease?
Affected areas may be itchy and sore, and the skin may have an unpleasant odor, particularly in more moist areas such as the underarm and groin. Skin bacteria cause this issue. People with Darier disease have an increased chance of developing bacterial, fungal, and viral skin infections. These infections can cause the skin condition to flare up.
It is essential to know that affected individuals are more at risk of getting widespread “cold sores” (herpes simplex virus). If the skin condition suddenly gets worse and is much more painful than usual, this may indicate herpes simplex virus infection, even if there are no blisters or vesicles (small fluid-filled bubbles in the skin) as usually seen in ‘cold sores’ affecting the lip. Seek urgent medical advice if this happens.
How does it look like?
The rash usually appears in childhood / teenage years, but in some people, it is not present until adulthood. It mainly affects areas of the skin where there is the most grease production (sebaceous regions), which typically include the face, scalp, chest, neck, and upper back.
The appearance of the rash varies from small scattered, slightly greasy or waxy brownish, yellowish, or sometimes red skin lumps (papules), to larger thickened patches which may be crusty or scaly.
In the skin folds, particularly in the groin area and underneath the breasts, the skin may be more prone to becoming raw and starting to weep.
The fingernails are usually affected by red or white lines running the length of the nails and small notches at the ends of the nail. Nail changes and flat “warts” on the backs of the hands can often be seen in children with Darier disease several years before there are any other skin changes.
Pits or small areas of hard skin occur on the palms of the hands and, less often, the soles of the feet. Occasionally there may be tiny spots inside the mouth, and these may give the roof of the mouth a rough feeling.
How will it be diagnosed?
The diagnosis can often be made on the appearance of the rash and the fact that it runs in families. For confirming the diagnosis, your dermatologist may take a small sample of skin (called a biopsy) that will be examined under a microscope in the laboratory.
Can Darier disease be cured?
No, there is no cure, but there are many ways of managing the affected skin. A quarter of patients notice that the condition may improve over time. There are treatments available to try and control the disease, but it can recur and worsen again after treatment.
How can Darier disease be treated?
Simple measures such as wearing cotton clothing, minimizing sweating, and using sun protection may reduce symptoms.
Topical treatments: Moisturising creams, corticosteroid creams, 5 fu cream, calcineurin inhibitors agents are available
Antiseptic solutions for washing and antiseptic creams may be helpful, mainly if there is a problem with odor. Creams and washes containing antiseptics such as chlorhexidine may help reduce the tendency to get a secondary infection.
Oral Treatments: If a bacterial infection is severe, oral antibiotics may be required, and widespread cold sore infections (herpes simplex) require treatment with oral anti-viral treatment, usually acyclovir. For more severe disease, treatment with the oral Retinoids Acitretin or Isotretinoin may be tried. These are usually given long term to keep the skin under control. They must not be used during pregnancy. Ciclosporin is sometimes used ‘off-license’ to help control Darier disease (a license for a drug says how it should be used; ‘off-license’ means that it is used in a way that is not described in this license).
Other useful treatments: Laser treatment or resurfacing of very dense areas have been reported to be successful and may be offered by some dermatology departments. Surgical excision or Dermabrasion (removing surface layers) of very thick regions has been used occasionally. Photodynamic therapy, a type of photochemotherapy delivered in dermatology departments that is used to treat other skin conditions (e.g., Actinic Keratosis) has been used effectively in some cases of Darier disease.
Botulin toxin injections can be helpful for severe Darier disease of the skin folds as they reduce sweating, and this option can be discussed with your dermatologist.