DARIER'S DISEASE

 


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DARIER'S DISEASE

This disease was first described in 1889 by Jean Darier, a French dermatologist. It is a rare condition characterised by itchy, warty bumps often involving the chest, neck and upper back. The condition can affect both men and women.

Symptoms
The first signs of the condition usually appear between the ages of 6 and 20, but may begin when people are older or, rarely, younger. The severity of the condition varies enormously and is unpredictable. Small brownish, rough topped bumps develop on the skin. Some patients have scattered spots which cause very little trouble, but in others the disease is more pronounced. The chest, neck or upper back are often involved at the beginning, but warty bumps may occur on any part of the body. It is unusual for people to have much trouble on the face, except for the skin on the forehead near the hairline. The scalp and skin around the ears may be scaly and itchy and most people notice some small spots in the armpits, the groin or, in women, under the breasts.

The fingernails are usually affected. They tend to be rather fragile, split easily and look as if they have been bitten or appear dirty. There may be very obvious long red or white lines running the length of the nails. Nail changes or flat warts on the backs of the hands are often present in childhood, before other symptoms appear. Pits or small corns occur on the palms of the hands and less often the soles of the feet. Occasionally there may be small spots inside the mouth, which give the roof of the mouth a rough feeling.

Although the condition is not infectious or contagious, people with Darier's disease show an increased susceptibility to herpes simplex infections, which exacerbates the symptoms of the condition. Though the skin may be clean, affected areas may smell unpleasant, due to bacterial growth in the rash. The condition is aggravated in the summer months due to an inherent photosensitivity, and through stress.

Causes
It is a dominantly inherited condition. There is a 1-in-2 chance that each child of an affected parent will inherit the disease.

The condition is caused by a change (mutation) in a gene on chromosome 12. This gene makes a protein found within keratinocytes called SERCA2. The SERCA2 protein acts as a &'calcium pump'.

Cells use calcium to produce signals that control the complicated &'machinery' inside the cell. In Darier's disease we believe signalling is faulty in the skin because the calcium pumps do not work properly. This leads to breakdown in the normal bonding of skin cells. The skin becomes scaly, lumpy and may blister.

Treatments
Retinoids (Vitamin A derivatives) are taken orally and improve the overall condition of the skin, by reducing its lumpiness and scaling, in most patients. Care must be exercised when prescribing to sexually active women, as retinoids could damage an unborn child. Therefore retinoids are only prescribed to sexually active women who have been sterilised, or who are using an effective contraceptive. Retinoids also cause the drying of lips, eyes and nose and patients with mild forms of the disease often decide to live with the symptoms of the condition rather than these side effects.

Itching (pruritus) is very common. Emollients containing an anti-pruritic may relieve some of the irritation. More severe pruritus can be controlled with a corticosteroid cream, containing an antibiotic to prevent skin infection. As mentioned the affected skin may smell unpleasant, particularly in moist areas, due to a bacterial growth in the rash. This does not mean that the skin is dirty. Careful washing is important, and antiseptic solutions for the bath, as well as creams or antibiotics may help.

The condition can be exacerbated by heat, sweating and, wool or nylon clothing. Some patients find that sunlight causes the skin to flare up, whilst some women find the condition worsens around the time of their period.

In a quarter of patients the condition improves as they get older. Most people lead full and active lives, with less than a quarter needing time off work or school because of the condition.

 



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