<prompt> In spider nevi, dilatation of blood vessels is due to:TestosteroneEstrogenHepatotoxinsFSH  <response>: Ans. B EstrogenRef: WikipediaA spider angioma also known as a nevus araneus, spider nevus, vascular spider, and spider telangiectasia is a type of telangiectasis found slightly beneath the skin surface. The central red dot is the dilated arteriole and the red spider legs are small veins carrying away the freely-flowing blood. The dilation is caused by increased estrogen levels in the blood. 