Oral manifestations in Urbach--Wiethe disease (lipoglycoproteinosis; lipoid proteinosis; hyalinosis cutis et mucosae).

The oral manifestations in 27 patients with Urbach--Wiethe disease (UWD) discovered in Northern Sweden are described. The oral regions most frequently affected are the lips, the back of the tongue, the frenulum of the tongue, the palate and the back wall of the pharynx. The general impression is that older patients usually have more marked manifestations than younger, indicating that the oral lesions may become more severe with increasing age. Histopathologically, the disorder is essentially a microangiopathy in which the walls of small blood vessels are thick and PAS-positive, indicating the presence of glycoproteins. In clinically affected regions there are usually PAS-positive extravascular deposits. In material used of lipid histochemical studies, sudanophil droplets were found in the vessel walls. By staining with osmium tetroxide the osmium is--contrary to previous assumptions--in some way bound to the droplets, but for unknown reasons is not reduced to a coloured product. The binding of osmium was demonstrated by the OTAN (osmium textroxide alpha-naphthylamine) method. The exact significance of this finding awaits further studies. The implications of dental anomalies occurring in UWD are discussed.