Darier's Disease, Darier-White Disease, Keratosis Follicularis

 

Definition: Darier's Diseases is a slowly progressive inherited disorder of keratinization of the skin. The lesions of this disorder typically appear as small skin-colored bumps about the size of a pinhead or pea. These bumps occur most prominently on the chest, back, scalp, forehead, and groin, and often occur in relation to a hair follicle. The disease can also appear in areas devoid of hair follicles, like the mouth, nail beds, palms, and soles. The most severe form occurs in late childhood and occurs equally in boys and girls. There is a milder form which occurs in adulthood, and is characterized by scattered lesions on sun exposed areas of skin which last any where from several months to years.

 

Cause: Darier's disease is an autosomal dominant inherited disease caused by premature keratinization of cells in the epidermis. Sun exposure and minor physical trauma both appear to play an important role in the development of the lesions, though the precise cause is still unknown.

 

Progression: Initially the disease may be mistaken for acne when it involves on the face and shoulders, or seborrheic dermatitis when it involves the scalp. These bumps are itchy, and as the disease progresses, may become malodorous. The lesions may group together to form plaques and warty masses which are at risk of becoming secondarily infected. Areas that typically may become infected include the face, groin, thighs, and over the shins. The symptoms are worsened by sunlight, and consequently the lesions are worse on sunexposed areas and during the summer. It is not uncommon for there to be a delayed effect of sunexposure, with a exacerbation occurring after the patient returns from a vacation. High heat and humidity may also cause the disease to worsen. Lesions that occur in the mouth appear as white bumps with a centrally depressed area on the gums, palate, and inside of the cheeks. On the palms and soles the lesions may appear as minute pits and punctate keratosis. Scalp involvement may result in permanent areas of hair lose.

 

Diagnosis: The diagnosis of Darier's disease is confirmed by biopsy of a lesion with microscopic examination. Microscopically there are two types of cells that are characteristic of Darier's disease. These are termed "corps ronds" and "grains." These cells result from prematurely keratinized cells. These cells are contained in clefts above the basal layer which form from faulty epidermal cohesion.

 

Treatment: For mild disease, no medical treatment is necessary except for a simple emollient. The patient should also avoid sunshine and high heat. The most impressive results have occurred with the use of oral synthetic retinoids. Although the long term effects of chronic therapy are still undetermined, significant remission of the disease may occur. Also useful are keratolytic agents like a salicylic acid in propylene glycol gel to remove the crusts. In the past the disease was thought to be due to a vitamin A deficiency, and oral vitamin A was given, but with unimpressive results. More effective appears to be topical vitamin A acid, but irritation commonly results in stopping the therapy. Because secondary infections may be common, topical or systemic antibiotics may become necessary to control the infections which occur in the lesions.

 

Prognosis: Resolution of the disease has occurred without medical intervention, but generally the condition runs a chronic, relapsing course with minor fluctuations in severity related to seasonal and hormonal changes. The overall health of the individual, though, largely remains unaffected.