What Is Acute Flaccid Myelitis?

Reviewed by: Mary L. Gavin, MD

What Is Acute Flaccid Myelitis?

Acute flaccid myelitis (AFM) is a rare condition that affects the spinal cord. It comes on suddenly and makes muscles weak and floppy.

What Are the Signs & Symptoms of Acute Flaccid Myelitis?

Acute flaccid myelitis often happens after a respiratory infection, such as a cold.

A child with AFM usually has sudden weakness in the arms and legs. Other signs of acute flaccid myelitis include:

  • drooping eyelids
  • trouble moving the eyes
  • drooping mouth
  • slurred speech
  • trouble swallowing
  • trouble breathing

If you or your child have any of these symptoms, get medical care right away.

What Causes Acute Flaccid Myelitis?

Experts think that or toxins in the environment might cause acute flaccid myelitis.

AFM is not a new problem, but many people are learning about it now because of the recent outbreaks. Experts don't know what's causing the increase in cases.

Acute flaccid myelitis is still very rare (fewer than 1 in 1 million people per year in the United States). It usually affects children.

What Might Help Prevent AFM?

Because viruses might cause AFM, avoid spreading germs by:

For updated information about acute flaccid myelitis, visit the CDC's AFM page.

Reviewed by: Mary L. Gavin, MD
Date reviewed: October 2018