Synonyms: Perianal Thrombosis, AnalthrombosisIn perianal vein thrombosis a blood clot (thrombus) is formed in the superficial veins at the edge of the anus, which manifests itself as a bluish knot. The causes for the development of thrombosis can be varied, but those affected also complain of severe pain. In general, perianal vein thrombosis is harmless, although painful. There is no connection to the much more dangerous deep leg vein thromboses or to varicose veins. Perianal vein thrombosis is often confused with hemorrhoids, which is why the term “fake hemorrhoids” is also commonly used.
Causes
The cause of perianal vein thrombosis is in most cases a strong increase in pressure in the abdominal cavity, for example when pressing strongly during bowel movement or during childbirth. Many women develop perianal vein thrombosis following delivery. Severe coughing or excessive physical activity, but also a genetic predisposition, can promote the development of perianal vein thrombosis.
Coffee and alcohol consumption, as well as the consumption of strongly seasoned food, should also be beneficial. Predominantly sedentary activities can promote perianal vein thrombosis, especially sitting on cold surfaces. Last but not least, women with perianal vein thrombosis are also thought to be associated with menstruation.
If diarrhea or proctological operations or anal sexual practices have been performed previously, these factors may also be the cause of anal venous thrombosis. In addition, perianal venous thrombosis occurs more frequently in persons who have large hemorrhoidal cushions. These mentioned causes can also lead to pelvic vein thrombosis. This is problematic due to its asymptomatic course, which is why it can be detected too late.
Symptoms
In perianal vein thrombosis, one or more bluish, bulging elastic nodes develop at the edge of the anus, which are usually very painful when palpated or pressed. The anal region can be swollen around the nodes. The size of the blood clots varies between cherry stone and (more rarely) plum size.
Depending on the severity of the findings, sitting or walking may also be painful for those affected. The symptoms usually appear very suddenly. Some patients also experience a burning, stabbing or itching sensation. In particular, bowel movements are often associated with severe pain for those affected.
