What is the treatment for a firm, bluish, perianal nodule covered with skin causing severe pain in the rectum?

Treatment of Thrombosed External Hemorrhoid

The optimal treatment for a firm, bluish, perianal nodule causing severe pain is office-based excision under local anesthesia, which provides immediate pain relief and prevents prolonged symptoms. 1

Confirming the Diagnosis

This clinical presentation is pathognomonic for a thrombosed external hemorrhoid (also termed perianal thrombosis), characterized by:

• Acute-onset severe anal pain with a palpable perianal lump 1
• Bluish discoloration from venous engorgement with clot formation 1, 2
• Location below the dentate line (external) 1
• Pain distinguishes this from uncomplicated internal hemorrhoids, which are typically painless 1

Critical pitfall: Do not assume all perianal lumps are hemorrhoids—up to 20% of patients have concomitant anal fissures, and perianal abscesses can present similarly but require different management. 1, 3

Treatment Algorithm

Acute Presentation (Within 72 Hours of Symptom Onset)

Surgical excision is superior to conservative management for acute presentations and should be performed immediately: 1

• Technique: Use multiple counter-incisions rather than a single long incision to prevent step-off deformities and delayed wound healing 1, 3
• Perform under local anesthesia in the office setting 1
• Excision provides immediate pain relief versus 7-10 days with conservative management 1

Subacute Presentation (>72 Hours or Symptoms Resolving)

If pain is already resolving spontaneously, excision is not required as symptoms typically resolve within 7-10 days: 1

Pharmacological management options:

• Topical nifedipine 0.3% with lidocaine 1.5% applied every 12 hours achieves 92% resolution at 14 days versus 45.8% with lidocaine alone 1
• Short-term topical corticosteroids (maximum 7 days only) to reduce inflammation, but must be limited to avoid mucosal thinning 1
• Oral paracetamol or ibuprofen for moderate to severe pain 1

Conservative measures:

• Increased dietary fiber and water intake to prevent straining 1
• Improved perianal hygiene 1

When to Suspect Alternative Diagnoses

Red flags requiring urgent evaluation: 3, 1

• Fever, systemic symptoms, or extensive cellulitis → suggests perianal abscess requiring surgical drainage 3
• Tender, indurated area above the anorectal ring on digital examination → intersphincteric abscess 3
• Pain without visible external lesion → small intersphincteric abscess 1
• Postdefecatory pain as cardinal symptom → anal fissure 1

Perianal abscesses require prompt surgical drainage to prevent expansion into adjacent spaces and systemic infection. 3 Complex abscesses (perianal/perirectal) respond to incision and drainage with adjuvant broad-spectrum antibiotics covering Gram-positive, Gram-negative, and anaerobic bacteria if systemic signs are present. 3

Recurrent Cases

For patients with multiple recurrences of perianal thrombosis, excision of the perianal skin and underlying external venous plexus (low hemorrhoidectomy) is indicated, leaving anterior and posterior skin bridges. 2 This addresses the underlying pathology—these lesions are true thrombi within thin-walled vessels of the external anal plexus, not simple hematomas. 2