Differential Diagnosis for Anal Irritation

• Single most likely diagnosis
  • Hemorrhoids: This is often the most common cause of anal irritation due to inflammation of the veins in the rectum or anus, leading to discomfort, itching, and sometimes bleeding.
• Other Likely diagnoses
  • Anal fissure: A small tear in the lining of the anus, causing pain and bleeding during and after bowel movements.
  • Pruritus ani (anal itching): A condition characterized by intense itching around the anus, which can be caused by various factors including diet, hygiene, and skin conditions.
  • Fecal incontinence or leakage: Inability to control bowel movements, leading to irritation and discomfort.
  • Anal eczema or dermatitis: Skin conditions that can cause itching, redness, and irritation around the anus.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Anal cancer: Although rare, it's crucial to rule out as it can present with similar symptoms and has a significant impact on prognosis if not caught early.
  • Inflammatory bowel disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause anal irritation among other symptoms and require prompt treatment.
  • Infectious diseases (e.g., herpes simplex, syphilis, gonorrhea): These can cause anal irritation and have significant health implications if not treated properly.
• Rare diagnoses
  • Lichen sclerosus: A rare skin condition that can cause itching, pain, and scarring in the anal area.
  • Hidradenitis suppurativa: A chronic skin condition that can cause painful abscesses and nodules in the anal and genital areas.
  • Pilonidal sinus or cyst: A congenital condition or acquired through injury, causing a cyst or abscess at the base of the tailbone, which can irritate the anal area.