The appendix testis is a small tag that lies on top of the testis (TESS-tis). It doesn't have a function and isn't needed. But if it becomes twisted (called torsion), it can get red, swollen, and painful. 

Torsion of the appendix testis (also called appendix testis torsion) usually goes away on its own and doesn't cause any serious or long-lasting problems. Treatment usually includes rest, pain relievers, and scrotal support.

Follow your health care provider's recommendations on:

• How long your child needs to rest in bed.
• When your child can go back to school and activities.
• How to use the scrotal support device.

To help keep your child comfortable until the pain gets better:

• If your health care provider says it's OK, you can give acetaminophen (Tylenol^® or store brand) or ibuprofen (Advil^®, Motrin^®, or store brand) as directed.
• If it's soothing, your child can place an ice pack wrapped in a towel on the scrotum for 10 minutes at a time a few times a day.

The pain:

• does not start to get better in about 2 days
• does not go away within 5–7 days

Your child's pain or swelling gets worse or they start vomiting.

What causes torsion of the appendix testis? Doctors don't know why the appendix testis sometimes twists. It might be that its shape makes it prone to twisting. It happens most often in boys 7–12 years old.

Can torsion of the appendix testis happen again? Most kids who have it once don't get it again and aren't likely to have other problems. But if your child has pain in the testicle again, it's important to have them checked by a health care provider right away. It could be a sign that the whole testicle (not just the appendix testis) has twisted. This is called testicular torsion, which is a medical emergency that needs treatment right away.

What happens if the pain doesn't get better? In most kids, the pain gets better in a day or two and is gone within 5–7 days. Although it doesn't happen often, some kids have continued pain and need to have surgery to remove the appendix testis.