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Thrombosed external hemorrhoid

Last updated: January 5, 2018

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A thrombosed external hemorrhoid is a localized thrombosis of the inferior hemorrhoidal venous plexus that results in severe, acute anal pain. Perianal clinical examination reveals a bulging, purplish nodule that is very tender to palpation. It may be treated conservatively with analgesic creams and steroids or be surgically excised for immediate pain relief.

External hemorrhoids are located distal to the dentate (pectinate) line; and are drained by the inferior hemorrhoidal (rectal) plexus. External hemorrhoid thrombosis occurs if a clot forms in the inferior hemorrhoidal plexus.




  • Acute onset of severe pain
  • Pain with defecation
  • May ulcerate and bleed
  • Thrombosed hemorrhoid detectable on rectal exam: palpable, bulging, dark red to purplish nodule at the outer rim of the anal canal; very tender to palpation

If the patient also presents with systemic symptoms such as weight loss, night sweats, or abdominal pain, underlying malignancy or infection must be ruled out!



The differential diagnoses listed here are not exhaustive.




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