What is a major oral manifestation of hereditary telangiectasia?

Hereditary telangiectasia, also known as Osler-Weber-Rendu syndrome, is characterized by the presence of numerous small, dilated blood vessels (telangiectasias) that can be seen on the skin and mucous membranes. One of the primary oral manifestations is the blanching of the oral mucosa when pressure is applied to the affected areas. This occurs because the telangiectasias are composed of fragile blood vessels that fill with blood upon pressure and empty out, resulting in a paler appearance during the blanching effect. Thus, the significant oral manifestation associated with hereditary telangiectasia is indeed blanching.

Other options, such as ulceration, localized swelling, and difficulty swallowing, are not typical or hallmark features of hereditary telangiectasia. While these symptoms can be present in other oral or systemic conditions, they are not directly related to the manifestations of hereditary telangiectasia, where the defining characteristic is the presence of telangiectasias leading to blanching.