Keratosis follicularis, commonly known as Darier disease, is a rare genetic disorder affecting the skin. Characterized by wart-like blemishes, this condition presents unique challenges in dermatological practice.
Etiology and Pathogenesis
Darier disease is an autosomal dominant disorder resulting from mutations in the ATP2A2 gene, which encodes the sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA2) pump. This mutation leads to impaired calcium regulation within keratinocytes, causing abnormal adhesion and differentiation of skin cells.
Clinical Manifestations
The hallmark of Darier disease includes:
- Wart-like Papules: Yellowish, greasy, and hard papules predominantly on the scalp, forehead, upper arms, chest, back, knees, elbows, and behind the ears.
- Nail Abnormalities: Longitudinal red and white streaks, nail fragility, and V-shaped notches at the free edge.
- Mucosal Involvement: Lesions on the palate, tongue, gums, and inside the cheeks and throat.
- Pruritus: Itching is common, and lesions may emit a strong odor.
Diagnosis
Diagnosis is primarily clinical, supported by:
- Histopathology: Acantholysis and dyskeratosis observed in skin biopsies.
- Genetic Testing: Identification of ATP2A2 gene mutations.
Management Strategies
Treatment focuses on symptom alleviation and includes:
- Topical Therapies: Use of emollients, keratolytic agents, and retinoids to reduce scaling and hyperkeratosis.
- Systemic Retinoids: Acitretin or isotretinoin for severe cases.
- Antibiotics: For secondary bacterial infections.
- Lifestyle Modifications: Sun protection and avoidance of heat and humidity to prevent flare-ups.
Understanding the genetic basis and clinical presentation of Darier disease is crucial for effective management. Ongoing research into targeted therapies offers hope for improved patient outcomes.
