External Hemorrhoid Thrombosis

What is an External Hemorrhoid Thrombosis?

A hemorrhoid thrombosis refers to a painful firm lump under the skin surrounding the anus. This is caused from a blood clot in an external hemorrhoid. If left untreated the thrombosis may swell and cause hemorrhoid prolapse which causes severe pain. 

What Causes an External Hemorrhoid Thrombosis?

A number of things, such as constipation, prolonged sitting or standing, pregnancy, heavy lifting or exercise, air travel, diarrhea, straining, or previous blood clots can lead to an external hemorrhoid thrombosis. 

Pressure in the pelvis can sometimes slow the blood flow to the skin around the anus, causing a blood clot. The clot can then swell which is extremely painful in the first couple of days. 

Diagnosing a Hemorrhoid Thrombosis

A hemorrhoid thrombosis is a hard blue lump on the outside of the anus. It is typically tender, so much so that the pain can limit the ability to complete an initial exam. A thrombosis can cause a portion of the overlying skin to die leading to a drainage of blood. During the initial exam, we may use creams to ease the pain from the thrombosis. A proper rectal exam and anoscopy are necessary to exclude other conditions and to determine the presence of enlarged internal hemorrhoids.

Treating External Hemorrhoid Thrombosis

Smaller, minimally painful blood clots can typically be treated with over-the-counter pain meds, soaking in warm water, stool softeners, or topical analgesics like lidocain or prilocaine. The thrombosis is usually dissolved by your body's natural defenses over the course of a few weeks. It can sometimes leave behind a small skin tag. 

Larger blood clots may rupture which causes bleeding. The bleeding, though worrisome to most, actually drains the clot which may help to decrease the pain. The amount of bleeding varies per patient. If at any time you feel worried, call your doctor or go to the nearest emergency room. Compounds such as nitroglycerin, diltiazem or other smooth muscle relaxers can help to decrease the spasm and the pain, speeding the recovery process up a bit. Sometimes these larger blood clots require surgical drainage. This procedure is typically done under anesthesia. 

A follow up exam is necessary to inspect the clot and asses if there are any internal hemorrhoids. The doctor will determine if rubber band ligation of the internal hemorrhoids is necessary. No treatment will completely eliminate the risk of recurring blood clots.