Shingles, or herpes zoster, is a reactivation of the varicella-zoster virus that causes chickenpox. Only people who’ve had chickenpox can develop shingles.

Shingles usually causes clusters of blisters and rashes. The most common place for it to develop is around one side of your waistline, but it also commonly appears on one side of your spine or face.

Although very uncommon, shingles can potentially develop on your penis. About a third of Americans develop shingles at some point in their life, but only a handful of case studies in medical literature describe people developing shingles on their penis.

Keep reading to learn why shingles can develop on your penis and how to recognize the symptoms.

More than 99 percent of people born before 1980 had chickenpox. Chickenpox symptoms generally clear up within 2 weeks. Even once the itchy spots go away, the varicella-zoster virus lays dormant in your spinal or cranial nerves.

The virus can remain for decades before reactivating. When it does reactivate, it causes a condition called shingles. Shingles usually causes blisters or rashes to form on your skin.

Most people develop shingles after the age of 50, and about half of the cases are in people over 60. The virus often becomes reactivated during a period of immunosuppression (weakened immune system) or stress.

Why your penis may be affected

Once the virus becomes reactivated, it travels down a sensory nerve until it reaches your skin. The part of your skin affected by shingles depends on which nerve the virus becomes active in.

The area of your skin that receives sensory information from a particular nerve is called a dermatome. For example, the dermatomes for the nerves that leave your spine at the level of your first lumbar spinal vertebra (L1) are in your lower back, hips, and groin.

Shingles usually appears in one or two side-by-side dermatomes.

Neural information from your penis is sent to your brain through the S2 and S3 nerves that are at the level of your sacrum bone. If the virus that causes shingles is activated in these nerves, you may develop shingles on your penis as well as your buttocks, groin, or thighs.

Case studies of penile shingles

A 2015 case study describes a 31-year-old man who developed shingles on his penis. The man developed a pins and needles sensation on his penis for 2 days before developing a rash that lasted for 10 days. He noticed a similar rash on his left thigh 3 days later.

A 2013 study describes a 67-year-old man who developed fatigue, pain in his urethra when urinating, and frequent urination that didn’t respond to antibiotics. When he went to the doctor, they also discovered he had penile numbness and a rash on his left buttock corresponding with his S2 and S3 dermatomes.

An older 2011 study describes two people with compromised immune systems developing penile shingles.

The first case was a 30-year-old-man who developed a rash on his inner groin and on the left side of his penis.

The second case was a 72-year-old man who developed a rash in his groin and severe pain in the areas corresponding with his S2 to S4 dermatomes. A physical exam revealed clusters of fluid-filled blisters on his penile shaft and left buttock.

Penile shingles can cause symptoms that are similar to those of genital herpes. It can be difficult to diagnose based on visual inspection alone.

Symptoms may include:

  • paresthesia (pins and needles sensations)
  • altered sensation in the glans penis (penile tip)
  • a rash that can extend to your groin
  • blisters
  • pain
  • itchiness

General symptoms include:

Shingles that affects your sacral nerves can also lead to bowel or bladder incontinence.

It’s very uncommon to develop shingles on your penis. In the 2015 case study mentioned earlier, the authors describe only being able to find a handful of case studies of penile shingles in medical literature.

The same authors also report that sacral nerves are involved in up to 5 percent of shingles cases. Your sacral nerves carry sensory information from your:

  • lower back
  • buttocks
  • back of legs
  • outer toes
  • genitals
  • heels

It’s important to seek medical attention as soon as possible if you develop shingles symptoms.

About 10 to 18 percent of people with shingles develop a type of long-term nerve pain called postherpetic neuralgia (PHN). A doctor can prescribe antiviral drugs that help reduce your chances of developing PHN and other complications.

It’s a good idea to contact a doctor any time you develop an unidentified rash on your penis. A rash can be a sign of the sexually transmitted infection (STI) genital herpes as well as some other STIs.

Shingles is a viral infection caused by the same virus that causes chickenpox. It causes a cluster of rashes or blisters, usually on your torso, waist, or face. In rare cases, it can form on your penis.

If you think you may have shingles, or if you have an unidentified penile rash, it’s important to seek prompt medical attention for a proper diagnosis and to minimize your chances of developing complications.