Also known as Darier-White disease, or
keratosis follicularis, Darier's disease is a rare inherited disease of
keratinization characterized by scaly, crusted papules typically occurring
on seborrheic areas. Mucous membrane and nail changes also occur.
ETIOLOGY & PATHOGENESIS
- Darier's disease is inherited as an autosomal dominant trait with high penetrance.
- The Darier's disease gene is located on chromosome 12 and encodes a adenosine triphosphatase calcium pump (SERCA 2).
- Mutations of the gene results in abnormality in epidermal cell-cell adhesion and premature and faulty keratinization leading to intraepidermal clefts and dyskeratotic cells.
- Precipitating factors include heat and humidity, mechanical trauma like friction, sunlight, and secondary bacterial infections.
CLINICAL FEATURES
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Darier's disease occurs in all races.
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Both sexes are equally affected.
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The onset of disease is during the first or second decade.
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Initial lesions are skin colored papules that develop scales or crust on its surface which, on removal may reveal a depression. The lesions gradually darken to take a brownish or blackish hue.
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The discrete, warty papules may coalesce to become crusted plaques. On intertriginous areas, vegetative lesions may become malodorous.
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The distribution is typically on the seborrheic areas: chest, back, back of ear, forehead, scalp, neck, nasolabial folds, groin, and axillae. In extensive disease, any area of the body may be involved. The affection is symmetrical.
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The scalp may show greasy scales.
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Localized, unilateral disease along Blaschko's lines may occur due to somatic mutation.
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Oral mucosa: whitish papules with central umbilications on gingiva, palate. Pebbly white plaques (cobble stoning) may also be found. Involvement of oropharynx, trachea and esophagus has also been described.
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Nails: Thinning of plate, subungual hyperkeratosis, longitudinal ridging, alternate, longitudinal white and red bands. V-shaped, triangular scalloping of distal nail plate is characteristic.
DIFFERENTIAL DIAGNOSIS
- Seborrheic dermatitis
- Hailey-Hailey disease
- Pemphigus vegetans
- Pemphigus foliaceus
- Grover's disease (transient acantholytic dermatosis)
- Localized form: epidermal nevus
- Histologic D/D: Epidermal nevus, warty dyskeratoma, actinic keratosis
DIAGNOSIS
- Family history of similar affection in parents/siblings.
- Typical clinical features of dirty, keratotic papules at sites of predilection.
- Histology:
Hyperkeratosis, parakeratosis, acanthosis
Suprabasal intraepidermal clefts
Acantholysis
Dyskeratotic cells in spinous layer ( corps ronds) and keratin layer
(grains)
COURSE AND PROGNOSIS
- Darier's disease runs a life-long course.
- Seasonal variations in severity occurs.
TREATMENT
- Avoidance of frictions/mechanical irritations.
- Use of sunscreens.
- Topical retinoids: tazarotene, adapalene
- Systemic retinoids: isotretinoin or acitretin may induce temporary remission.
- Topical and systemic antibiotics to treat secondary bacterial infections.
- Hypertrophic lesions may be treated with dermabrasion, excision and grafting, or laser excision.