Red dotted nevus on the body may be caused by spider nevus, vascular nevus or cherry angioma. 1. Spider nevus: the estrogen level in the blood plasma of patients with spider nevus is usually higher than that of normal people, and due to the effect of estrogen, it will cause the expansion of blood vessels as well as the formation of new blood vessels in the shape of spiders. 2. Vascular nevus: it may be caused by the use of certain cosmetics and hormonal drugs, which induces the expansion of blood vessels and the proliferation of cells, resulting in red nevus on the body. 3. Cherry angioma: cherry angioma is a benign skin lesion. It is usually due to the proliferation of local capillaries, which leads to the expansion of the ends of the proliferated capillaries, thus causing reddish naevus on the body. If you have a red nevus, you should go to the hospital in time, and give targeted treatment after clarifying the cause of the nevus.