Why does the penis hurt during erection in patients with pudendal neuralgia?

Penile Pain During Erection in Pudendal Neuralgia

In pudendal neuralgia, penile pain during erection occurs because the pudendal nerve provides sensory innervation to the penis, and when this nerve is entrapped or damaged, the increased blood flow and tissue expansion during erection mechanically stretches and irritates the already compromised nerve fibers, triggering neuropathic pain.

Mechanism of Pain

The pudendal nerve has both sensory and motor functions and influences autonomic pathways 1. When the nerve is injured or entrapped:

• Sensory nerve damage creates abnormal pain signaling along the penile shaft and glans, which are directly innervated by terminal branches of the pudendal nerve 2
• Mechanical stress during erection stretches the damaged nerve fibers as the corpora cavernosa expand, exacerbating neuropathic pain 1
• Impaired sensation of the glans and abnormal motor function of muscles participating in erection contribute to the pain syndrome 3

This differs fundamentally from diabetic autonomic neuropathy, which affects erectile function through autonomic pathways rather than direct sensory nerve damage 2.

Clinical Presentation Pattern

Patients with pudendal neuralgia typically experience:

• Sharp, burning pain along the course of the pudendal nerve that worsens with sitting 4
• Pain aggravated by activities that increase pelvic pressure or stretch the nerve, including erections 1
• Foreign body sensation and shooting pain in the perineal and penile regions 5
• Constellation of symptoms from nerve injury including both pain and functional impairment 1

Diagnostic Considerations

When evaluating penile pain during erection, consider pudendal nerve injury particularly in patients with:

• History of pelvic trauma or surgery (such as hysterectomy, pelvic procedures) 1
• Sensory changes in the perineal or genital region 2
• Pain that worsens with sitting for more than 10-15 minutes 4
• Positive response to diagnostic pudendal nerve blocks with local anesthetic providing temporary relief 4

Treatment Approach

Conservative Management First

• Medication trials including gabapentin, amitriptyline, and opioids, though these often provide only minor relief 4
• Physical therapy and occupational therapy targeting pelvic floor dysfunction 4
• Pudendal nerve blocks can provide diagnostic confirmation and temporary relief lasting several hours 4

Advanced Interventions When Conservative Fails

Pulsed radiofrequency (PRF) of the pudendal nerve offers promise as a minimally invasive option:

• Performed at 2 Hz frequency, 20 millisecond pulse width, for 120 seconds at 42°C 4
• Can provide relief lasting 1.5 years or longer with minimal complications 4
• Safer than continuous radiofrequency with less cellular destruction 4

Chronic pudendal neuromodulation (CPN) for refractory cases:

• Tined leads placed at the pudendal nerve in the ischioanal fossa or transforaminal at S3/S4 1, 6
• Provides complete or near-complete pain relief in approximately 30% of patients, with significant relief in another 50% 6
• More effective than repeated nerve blocks, with 8/9 patients rating it superior 6
• Can maintain efficacy for years, though approximately 25% may lose effectiveness over time 6

Surgical decompression remains an option but carries more severe adverse events compared to other interventions 7.

Treatment Selection Algorithm

1. Start with diagnostic pudendal nerve blocks to confirm the diagnosis 4
2. Trial conservative management for 3-6 months including medications and physical therapy 4
3. If inadequate response and positive nerve blocks, consider pulsed radiofrequency as next step 4
4. For persistent symptoms after PRF, proceed to chronic pudendal neuromodulation 6
5. Reserve surgical decompression for cases where less invasive options have failed 7

Important Caveats

• All interventions improve pain to a similar extent (mean VAS reduction of 2.73 cm), with no single treatment clearly superior 7
• Evidence quality is limited with heterogeneous patient populations, non-standardized treatments, and short-term follow-up in most studies 7
• Adverse events are inconsistently reported but more severe with surgical approaches 7
• Erectile dysfunction may coexist and should be evaluated and treated separately according to standard ED guidelines if present 3, 2

The key is recognizing that the pain during erection is a mechanical exacerbation of underlying nerve damage, not a vascular or psychogenic issue, which fundamentally changes the treatment approach from standard erectile dysfunction management.