A 52-year-old woman comes to the emergency department for rectal pain that started 2 hours ago. The pain is described as severe, burning, and exacerbated while sitting. Medical history is significant for chronic idiopathic constipation, for which she takes a fiber supplement. The patient has 4 children, all of whom were vaginally delivered. Family history is unremarkable. She does not use tobacco, alcohol, or illicit drugs. Temperature is 37.2 (99 F), blood pressure is 138/84 mm Hg, and pulse is 90/min. On physical examination, the patient appears in moderate distress due to pain. The abdomen is soft, nondistended, and nontender. Bowel sounds are normoactive. Anal examination reveals a small, exquisitely tender, bluish lesion at the anal verge. Which of the following is the most likely diagnosis?
Anal & perianal masses | |
Rectal prolapse |
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External hemorrhoid |
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Internal hemorrhoid |
|
Perianal abscess |
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Anogenital wart |
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Anorectal cancer |
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Skin tags |
|
This patient's acute rectal pain and bluish-appearing anorectal lesion are consistent with a thrombosed external hemorrhoid. Hemorrhoids represent abnormal dilation of the hemorrhoidal venous plexus and are categorized by their position in relation to the dentate line as either internal (proximal) or external (distal). Risk factors include constipation, abnormal defecation (eg, straining, prolonged sitting on the toilet), increasing age, and pregnancy.
Thrombosis typically occurs with external hemorrhoids and manifests as excruciating anorectal pain exacerbated by sitting. Direct visualization of a bluish (or purplish) bulge at the anal verge confirms the diagnosis. Anoscopy can make visualization easier and is useful if the diagnosis is in doubt. Initial management of thrombosed hemorrhoids includes sitz baths, stool softeners, and topical anesthetics (eg, lidocaine). External hemorrhoidectomy is needed for severe cases that fail to respond to conservative measures.
(Choice A) Condyloma acuminata (anogenital warts) present as fleshy, cauliflower-shaped masses. They are more common in individuals who engage in anal intercourse. Symptoms include itching, scant bleeding, and impaired anal hygiene.
(Choices B and C) Perianal abscesses, which can occur with Crohn disease, present as tenderness and swelling with erythema and induration of the overlying skin. The onset is more subacute than a thrombosed hemorrhoid, and fever is common. Other perianal manifestations of Crohn disease include fistulae, which present with malodorous, purulent fecal drainage as well as pain and itchiness. The external opening of a fistula should be apparent on examination.
(Choice D) Although internal hemorrhoids can thrombose, associated pain is typically mild or absent because they are less innervated than external hemorrhoids. Prolapsed internal hemorrhoids appear as pink or purple masses protruding through the anal verge; they may or may not be reducible.
(Choice E) Rectal prolapse is common in older women with multiple vaginal deliveries. Examination demonstrates an erythematous mass with concentric rings that prolapses through the anus with Valsalva. Patients typically experience incomplete bowel evacuation and anorectal mass sensation; severe pain is unexpected.
Educational objective:
Thrombosis of an external hemorrhoid manifests as excruciating anorectal pain exacerbated by sitting. Examination demonstrates a bluish (or purplish) bulge at the anal verge. Initial management includes sitz baths, stool softeners, and topical anesthetics.