What Is Darier Disease?
Darier disease (keratosis follicularis or dyskeratosis follicularis) is an inherited skin disease that presents with yellowish wart-like blemishes over the skin. The blemishes are hard in consistency and emit a strong odor. They can frequently involve the scalp, ears, forehead, chest, and upper arms. The nail formation also changes with grooves and painful fissures. Dentists can detect this disease even in the asymptomatic (without symptoms) stage, as about 50 percent of these patients have oral manifestations. Hence, dental diagnosis plays an important role in the management of these lesions.
What Is the Etiology of Darier Disease?
The etiology of Darier disease is a group of structural disorders that occur in cell adhesion complexes, such as the components of desmosomes (junctions between cells). The structural disorder triggers an auto-immune reaction amongst the skin cells causing the clinical symptoms of this disease. More recently, research shows that certain mutations in the gene encoding the endoplasmic reticulum (a cell structure responsible for protein synthesis, lipid metabolism, and calcium storage) is responsible for the lack of structural maturation of the cell adhesion complexes.
What Are the Oral Manifestations of Darier Disease?
Oral lesions of Darier disease are asymptomatic and identified during routine dental examination.
- Site: Primary intraoral lesions of Darier disease affect the hard palate and alveolar mucosa (covering the upper and lower bony ridges). Secondary intraoral lesions occur on the oral mucosa or the tongue. Further, some patients can present with itchy and crusted lips.
- Appearance: The lesions appear as multiple firm papules (raised spots) with a central depression and a normal, whitish, or reddish color. The papules are reddish and may join to form crusts that lead to ulceration.
- Intensity: Clinically, the oral manifestations of Darier disease are moderate to severe in intensity. In the moderate form, the dentist may observe lesions similar to nicotine stomatitis (a white patch on the hard palate due to smoking). In contrast, the severe form resembles inflammatory fibrous hyperplasia (proliferative tissue lesion due to trauma).
- Additional Findings: Research suggests that 30 percent of patients suffering from this disease have intermittent sialadenitis (recurrent salivary gland swelling). Intermittent sialadenitis is a rare condition affecting the salivary glands originally described by Spouge in 1966.
What Is the Differential Diagnosis of Darier Disease?
Darier disease is similar to many skin diseases. Hence, the differential diagnosis (distinguishing a condition with similar features) should include Hailey-Hailey disease, Grover's disease, and pemphigus vulgaris. These three diseases also have a split in the skin layers (called suprabasal split), similar to Darier disease. The key to differentiating between these diseases is prominent cell necrosis (death) in pemphigus vulgaris. On the other hand, cell necrosis is much rarer in Hailey-Hailey and Darier disease. Also, the clinical signs of Darier disease and oral manifestations must be considered to establish a confirmatory diagnosis by the physician and the dentist.
How Are the Oral Lesions of Darier Disease Managed?
The systemic treatment of Darier disease is based on the patient's clinical symptoms and extent of discomfort. For those patients suffering from severe and generalized forms of the disease, they are treated with topical and oral retinoids (vitamin A compounds) by the physician. However, therapies for the oral manifestations mentioned in studies aim at improving the patient’s quality of life concerning esthetics and oral hygiene.
- In patients with persistent oral lesions, topical retinoids are an effective therapy. Studies reveal that topical retinoids achieve a modest reduction of symptoms in 90 percent of patients. They further reduce hyperkeratosis (skin thickening due to increased keratin), improve papules, and reduce halitosis.
- Strict oral hygiene is recommended by the dentist which is achieved by antiseptic mouth rinses use. Furthermore, because the coalescence of the papules on the oral mucosa leads to the accumulation and degradation of organic products (such as keratin), it leads to halitosis (bad mouth odor). Further, bacterial degradation in the oral cavity favors secondary infections.
- According to many authors, oral complications worsen when lesions are left untreated. Therefore, steroids and antibiotic prophylaxis are other strategies adopted by the dentist.
- Radical treatment options include surgical excision, abrasion, carbon dioxide laser application, or photodynamic therapy (PDT, which uses light and a drug to destroy abnormal cells). Studies show that PDT leads to sustained clearance or improvement of lesions over six months to three years. However, PDT is a potential adjunctive modality for Darier disease and should not be considered a substitute for retinoids in patients who require systemic treatment.
Regardless of the clinical severity, the implications of the Darier disease have a profound impact on the patient's cosmetic and esthetic outcomes. Other than the functional implications, patients suffering from the disease are more concerned about the esthetic appearance. Since it is primarily a dermatosis (a skin lesion), it is pertinent for the physician and dentist to collaborate and coordinate to treat both oral and skin lesions. Patients must be referred to a dermatologist and informed about possible complications such as halitosis, dental caries, and secondary oral infections. Also, a psychiatric opinion must be taken in more severe cases. Therefore, it is important to ensure a multidisciplinary approach in the management of patients with Darier disease.
Conclusion
Darier disease is an oral diagnostic challenge, but early diagnosis and treatment can improve patient prognosis. It is pertinent that patients with Darier disease receive genetic counseling on the nature of their inherited condition and the risk of transmission to their offspring. Also, the dentist should prioritize and diagnose the oral manifestations in routine examination visits, even when the lesions are asymptomatic. However, a biopsy is needed to confirm the final diagnosis. Therefore, the patient should then be further referred for dermatological examination based on the results. Finally, patients should be duly informed of the oral complications of this disorder.
