Hereditary benign intraepithelial dyskeratosis (HBID), also known as Witkop’s disease, is a rare autosomal dominant disorder characterized by oral lesions and bilateral limbal conjunctival plaques.
This condition is noted specifically in a triracial isolate of white, Native American, and African American people and their descendants in Halifax county, North Carolina. It exhibits a high degree of penetrance.
FEATURES
The oral lesions are similar to those of WSN, with thick, corrugated, asymptomatic, white “spongy” plaques involving the buccal and labial mucosa. Other intraoral sites include the floor of the mouth, the lateral tongue, the gingiva, and the palate. The oral lesions are generally detected in the first year of life and gradually increase in intensity until the teens. The most significant aspect of HBID involves the bulbar conjunctiva, where thick, gelatinous, foamy, and opaque plaques form adjacent to the cornea. The ocular lesions manifest very early in life (usually within the first year). Some patients exhibit chronic relapsing ocular irritation and photophobia. The plaques may exhibit seasonal prominence, with many patients reporting more-pronounced lesions in the spring and regression during the summer months. A few cases of blindness due to corneal vascularization following HBID have been reported.
The histopathologic features of HBID are characteristic, and the epithelium exhibits marked parakeratin production with thickening of the stratum spinosum and the presence of numerous dyskeratotic cells. Ultrastructural findings in patients with HBID reveal the the presence of numerous vesicular bodies in immature dyskeratotic cells, densely packed tonofilaments within the cytoplasm of these cells, and the disappearance of cellular bridging in mature dyskeratotic cells.
TREATMENT
Since HBID is a benign condition, no treatment is required for the oral lesions. For evaluation and treatment of the ocular lesions, the patient should be referred to an ophthalmologist.
The oral lesions are similar to those of WSN, with thick, corrugated, asymptomatic, white “spongy” plaques involving the buccal and labial mucosa. Other intraoral sites include the floor of the mouth, the lateral tongue, the gingiva, and the palate. The oral lesions are generally detected in the first year of life and gradually increase in intensity until the teens. The most significant aspect of HBID involves the bulbar conjunctiva, where thick, gelatinous, foamy, and opaque plaques form adjacent to the cornea. The ocular lesions manifest very early in life (usually within the first year). Some patients exhibit chronic relapsing ocular irritation and photophobia. The plaques may exhibit seasonal prominence, with many patients reporting more-pronounced lesions in the spring and regression during the summer months. A few cases of blindness due to corneal vascularization following HBID have been reported.
The histopathologic features of HBID are characteristic, and the epithelium exhibits marked parakeratin production with thickening of the stratum spinosum and the presence of numerous dyskeratotic cells. Ultrastructural findings in patients with HBID reveal the the presence of numerous vesicular bodies in immature dyskeratotic cells, densely packed tonofilaments within the cytoplasm of these cells, and the disappearance of cellular bridging in mature dyskeratotic cells.
TREATMENT
Since HBID is a benign condition, no treatment is required for the oral lesions. For evaluation and treatment of the ocular lesions, the patient should be referred to an ophthalmologist.