What is a spider mole?
Spider nevus is an idiopathic telangiectasia, which is formed by the expansion of the terminal branches of cutaneous arterioles. Generally does not protrude from the skin surface. The body of the nevus has a central point, and there are radial branches of small blood vessels around it, which looks like a spider, so it is called spider nevus.
Spider nevi vary in size, ranging from a few millimeters to a few centimeters in diameter, and often appear in the distribution area of superior vena cava, such as face, neck, chest, hands, shoulders and upper arms. These spider nevus can disappear after compression, and when the compression is released, blood can be seen filling outward from the center.
The occurrence of spider nevus may be related to the increase of estrogen level. When acute hepatitis, chronic hepatitis, liver cirrhosis and other diseases lead to liver function damage, the liver's inactivation of estrogen decreases, which leads to the increase of estrogen in the blood, which causes the arterioles to dilate and form spider nevus.
Spider nevus often occurs in patients with acute and chronic hepatitis, cirrhosis, severe hepatitis, liver cancer and liver necrosis. But the discovery of spider nevus does not necessarily mean that there is something wrong with the liver. A few normal people (10~ 15%) may also have spider nevus, such as adolescent girls. About 40% pregnant women also have spider moles. Spider moles on pregnant women will gradually disappear a few months after the baby is born.
Among pathological factors, besides liver disease, spider nevus may also appear in some other diseases, such as rheumatism, rheumatoid arthritis, systemic lupus erythematosus, Cushing's syndrome, vitamin B deficiency, xeroderma pigmentosum, hemochromatosis, Raynaud's disease and so on. It may also lead to spider nevus. The number of spider nevus is related to the severity of the disease.
What is a red mole?
Many people will mistake the "red mole" on their bodies for a spider mole and suspect that there is something wrong with their liver. Red nevus, named cherry hemangioma, is caused by local vascular proliferation. There are morphological differences between red nevus and spider nevus. Red nevus is usually multiple, bright red or cherry red, hemispherical or flat in the early stage, with a diameter of 65438±0.5mm, normal surrounding color and no pseudopodia caused by telangiectasia. Most of them can fade when pressed by hand, and then return to their original state after being released. Some of them can't fade completely when pressed because of some proliferation.
Red nevus is a normal physiological phenomenon, which will gradually increase with age. Red nevus is not malignant, does not affect health, and generally does not need treatment. But if there is trauma, it may lead to more bleeding. If it grows in an obvious part and affects the appearance, it can also be treated by laser, freezing and electrocoagulation.