Darier disease (DAR/ Darier disease/ Dyskeratosis Follicularis / Darier–White disease/ Keratosis follicularis) is a rare, often chronic, genetic disorder characterized primarily by non-contagious skin changes. Darier disease or Keratosis Follicularis is an autosomal disorder, meaning that a single gene inherited from one parent causes this disease. Like Hailey-Hailey disease, Darier Disease is also grouped as a hereditary acantholytic dermatosis. Skin changes commonly start in adolescence. Flare-ups of Darier Disease or Keratosis Follicularis are triggered by tight-fitting clothes, humidity, stress and sun exposure. Darier disease affects both men and women equally and is not contagious.
Majority of the patients develop symptoms of Darier Disease or Keratosis Follicularis before the age of 30. Many patients can also have this disease in a mild form of which they are not aware of. Individuals with severe Darier Disease have chronic relapsing-remitting symptoms. In some patients, the symptoms may resolve spontaneously. The rashes or lesions of Darier Disease or Keratosis Follicularis worsen upon exposure to sun and sometimes by corticosteroid use. Patients with Darier Disease or Keratosis Follicularis can have flare ups of this condition with bacterial infections. Patient’s overall health commonly will be good irrespective of the severity of this condition.
Treatment of Darier Disease or Keratosis Follicularis comprises of topical antibiotics and retinoids, oral antibiotics and retinoids, antiviral medications, use of sunscreen and moisturizers.
Causes of Darier Disease or Keratosis Follicularis
As mentioned previously, Darier Disease or Keratosis Follicularis is a genetic disorder and is passed on in an autosomal dominant manner. The defective gene which causes this disease is present on an autosome and a single defective gene from one parent is enough to cause this condition. However, not all the patients having this abnormal gene will have symptoms.
Mutations in the ATP2A2 gene cause Darier Disease or Keratosis Follicularis and this gene is present on chromosome 12q23-24.1. The exact method of how this abnormal gene causes Darier Disease or Keratosis Follicularis is not clear and is still under research.
Signs & Symptoms of Darier Disease or Keratosis Follicularis
Different individuals have different symptoms of varying degrees. Some have very mild symptoms, some have severe and some patients have very subtle symptoms which they do not notice at all. The following are the characteristics of Darier Disease or Keratosis Follicularis:
- Development of skin lesions or rashes which have scaly, greasy bumps.
- These lesions commonly develop on the face, around the nostrils, eyebrows, sides of nose and beard region, neck, chest and back.
- These rashes or lesions have a characteristic smell.
- Skin folds such as armpits, groins, under the breasts and area between buttocks are often affected.
- The bumps can be skin-colored, brown or yellowish-brown in color.
- The bumps are firm to touch and are coarse in texture.
- Small bumps can grow together and form a larger lesion which is warty in appearance and foul smelling.
- The scalp commonly has a severely crusted rash resembling the rash of seborrhoeic dermatitis; the difference being this rash is coarse to touch.
- Some patients can develop flat, freckle-like lesions; whereas some may have raised and large wart like lesions.
- Patient may also have cystic acne along with this condition.
- Patient also develops small indentations on the palms and soles.
- There also may be small areas of bleeding beneath the skin present on the palms, soles, top of the hands and feet.
- Many patients have broad, longitudinal stripes of reddish and white color on the nails.
- Mucous membranes of individuals with this condition have a white cobblestone appearance or tiny papules on them.
- There may also be overgrowth of the gums.
Investigations for Darier Disease or Keratosis Follicularis
Darier Disease or Keratosis Follicularis is commonly diagnosed upon physical examination and with family history; however, it can be confused for other skin problems also. For this reason, skin biopsy can be done to confirm the diagnosis.
Treatment of Darier Disease or Keratosis Follicularis
- Treatment is required if the symptoms are severe and bothersome to the patient.
- For mild cases of Darier Disease or Keratosis Follicularis, treatment is not usually required; however, patient should avoid stress, excessive humidity, heat and tight clothes and use moisturizers, sun block and wear the right type of clothes which absorb sweat and keep the body cool.
- For localized lesions, dermabrasion can be done.
- Topical retinoids are also prescribed and are beneficial.
- If the patient has secondary bacterial infection, then antibiotics are prescribed.
- Antiviral medications are prescribed if the patient has herpes simplex.
- For severe symptoms, oral retinoids can be prescribed, but these medications have serious side effects and need to be used with caution.
- Topical or oral antibiotics can be prescribed during flare ups.
- Ciclosporin and other prescription topical corticosteroids can be used during acute flare ups.
- Using sunscreen and taking vitamin C tablets helps in preventing flare ups in some patients.
- Patients should also maintain good hygiene to prevent flare ups.
- Topical creams like benzoyl peroxide also help with the flare-ups.