Differential Diagnosis for a 54-year-old Male with Urinary and Rectal Symptoms

Single Most Likely Diagnosis

• Urinary Tract Infection (UTI) or Prostatitis: Given the patient's symptoms of urinary urgency, frequency, and rectal pressure, along with irritation to the tip of the penis, a UTI or prostatitis is highly likely. The recent sexual activity without condom use increases the risk of sexually transmitted infections (STIs), but the symptoms more closely align with a UTI or prostatitis, especially considering the patient's age and medical history.

Other Likely Diagnoses

• Sexually Transmitted Infection (STI): The patient's history of being sexually active with multiple partners without using condoms puts him at risk for STIs such as gonorrhea, chlamydia, or trichomoniasis, which could cause urinary symptoms and irritation.
• Yeast Infection/Balinitis: Given the patient's wife recently self-diagnosed with a yeast infection and the patient had sexual intercourse with her before her symptoms developed, it's possible he could have a yeast infection causing irritation to the tip of the penis.
• Benign Prostatic Hyperplasia (BPH): Although the patient reports a normal PSA, BPH could still be a consideration given his age and symptoms of urinary frequency and urgency.

Do Not Miss Diagnoses

• Prostate Cancer: Despite a recent normal PSA, prostate cancer must be considered, especially if the patient's symptoms persist or worsen. A normal PSA does not entirely rule out prostate cancer.
• Septic Prostatitis: A severe infection of the prostate that can lead to sepsis, a life-threatening condition. The patient's symptoms of rectal pressure and urinary frequency could be indicative of a more severe infection.
• Kidney Stones: Although not directly related to the patient's sexual history, kidney stones could cause severe pain and urinary symptoms. It's crucial to consider this diagnosis to avoid missing a potentially serious condition.

Rare Diagnoses

• Reiter's Syndrome (Reactive Arthritis): A rare condition that can occur after certain bacterial infections, including STIs, leading to symptoms such as urinary frequency, conjunctivitis, and arthritis.
• Fournier's Gangrene: A rare but serious condition involving necrotizing fasciitis of the genitalia, which could present with severe pain and urinary symptoms. It's essential to consider this diagnosis due to its high morbidity and mortality if not promptly treated.