What are the common causes of cystitis in men?

Common Causes of Cystitis in Men

The most common causes of cystitis in men are urinary tract infections caused by gram-negative enteric organisms (especially Escherichia coli), sexually transmitted infections, and urological abnormalities or instrumentation. 1

Etiological Agents

Bacterial Pathogens

• Gram-negative enteric organisms:

  • Escherichia coli (most common overall)
  • Proteus mirabilis (particularly important in men due to urease production and risk of stone formation)
  • Klebsiella pneumoniae
  • Enterobacter cloacae
  • Serratia marcescens
  • Pseudomonas aeruginosa

• Gram-positive organisms:

  • Enterococcus faecalis
  • Staphylococcus saprophyticus
  • Staphylococcus epidermidis

Sexually Transmitted Pathogens

• Chlamydia trachomatis
• Neisseria gonorrhoeae
• Sexually transmitted enteric organisms in men who engage in receptive anal intercourse 1

Age-Related Differences

• Men <35 years: Cystitis is more commonly associated with sexually transmitted pathogens (C. trachomatis, N. gonorrhoeae) 1

• Men >35 years: Cystitis is more commonly associated with:

  • Gram-negative enteric organisms
  • Urinary tract abnormalities
  • Recent instrumentation 1

Risk Factors and Predisposing Conditions

1. Anatomical or functional abnormalities:

   • Benign prostatic hyperplasia (BPH) - significantly increases risk of complications 2
   • Urinary retention
   • Vesicoureteral reflux
   • Urinary tract obstruction 1

2. Instrumentation and procedures:

   • Recent urinary catheterization
   • Urological surgery
   • Cystoscopy or other urinary tract procedures 1

3. Medical conditions:

   • Diabetes mellitus
   • Immunosuppression
   • Prostate cancer
   • Neurogenic bladder 1

4. Sexual activity:

   • Being the insertive partner during anal intercourse (risk for enteric organism infection) 1
   • New sexual partners
   • Multiple sexual partners 1

5. Healthcare-associated factors:

   • Exposure to multidrug-resistant organisms
   • Extended-spectrum beta-lactamase (ESBL) producing bacteria 3

Diagnostic Considerations

Cystitis in men is generally considered a complicated urinary tract infection due to the anatomical structure of the male urinary tract and the high likelihood of underlying abnormalities 1. Unlike in women, uncomplicated cystitis is rare in men.

When evaluating men with symptoms of cystitis:

• Digital rectal examination should be performed to investigate prostate diseases 1
• Urine culture is essential for proper diagnosis and targeted therapy
• If urease-producing bacteria (like Proteus mirabilis) are detected, stone formation should be excluded 1
• Consider underlying prostatitis, which may present with similar symptoms 4

Treatment Implications

Due to the high likelihood of complicated infection in men with cystitis:

• Longer treatment durations are typically required (7-14 days) compared to women 1
• Fluoroquinolones (e.g., ciprofloxacin) are often effective due to good prostate penetration 5, 4
• Narrow-spectrum antibiotics (like pivmecillinam) may be effective as first-line treatment in uncomplicated cases 2
• Urological evaluation is often warranted, especially in recurrent cases 3

Key Pitfalls to Avoid

1. Failing to distinguish between cystitis and prostatitis - symptoms may overlap, but treatment duration differs significantly
2. Inadequate treatment duration - men typically require longer courses than women
3. Missing underlying anatomical abnormalities - urological evaluation is often necessary
4. Overlooking sexually transmitted infections in younger men
5. Not considering antimicrobial resistance - particularly important with increasing prevalence of ESBL-producing and fluoroquinolone-resistant strains 3

Remember that cystitis in men is rarely an isolated or uncomplicated infection and typically warrants a more comprehensive evaluation than in women.