How Do You Get Ramsay Hunt Syndrome? Justin Bieber's Condition, Explained

Pop star Justin Bieber revealed he has Ramsay Hunt syndrome—a neurological disorder that has paralyzed half of his face—in an Instagram video shared Friday.

"As you can probably see from my face, I have this syndrome called Ramsay Hunt syndrome," Bieber told fans. "And it is from this virus that attacks the nerve in my ear and my facial nerves and has caused my face to have paralysis."

The syndrome is thought to affect five out of every 100,000 people in the U.S. each year, developing equally among males and females, according to the National Organization for Rare Disorders. It's the second most common cause of facial paralysis not caused by injury or trauma.

"As you can see, this eye's not blinking; I can't smile on this side of my face; this nostril will not move, so there's full paralysis on this side of my face," Bieber said, explaining why he'd be canceling his upcoming shows.

Though Ramsay Hunt syndrome is rare, it is caused by something relatively common: the varicella-zoster virus—the same one that causes chickenpox and shingles. Here's what to know about the syndrome, including other symptoms and treatments of the illness.

Ramsay Hunt Syndrome, Explained

Ramsay Hunt syndrome is a rare neurological disorder caused by a reactivation of the varicella-zoster virus, the same virus that causes chickenpox and shingles. "It is a form of shingles that is relatively rare," infectious disease expert Amesh Adalja, MD, senior scholar at the Johns Hopkins Center for Health Security, told Health.

The virus can lie dormant in the body for decades or even a lifetime following a childhood case of chickenpox. Strong immune systems can keep the virus at bay, but a weakened immune system can allow the virus to reactivate, causing shingles, or in some cases Ramsay Hunt syndrome. It's unknown why reactivation of the virus causes Ramsay Hunt syndrome in some, and typical shingles in others, said Dr. Adalja.

In Ramsay Hunt syndrome, when the virus reactivates it affects the facial nerve, disrupting its function, according to Dr. Adalja. It can make the facial muscles feel weak or stiff and results in difficulty smiling, wrinkling the forehead, or closing the eye on the affected side.

In most cases of Ramsay Hunt syndrome, a red, painful rash will also show up on the outside of the ear and external ear canal; sometimes, it will affect the mouth, soft palate, and top portion of the throat. But those two characteristic symptoms don't always happen together or at the same time. Hearing issues and ear pain can result from the virus too. Some people may experience ear pain, tinnitus (ringing in the ear), or hearing loss, which is often temporary.

Because Ramsay Hunt syndrome is reminiscent of other conditions, like Bell's palsy, diagnoses are often missed or delayed, according to researchers. But diagnosis—done through clinical evaluation and a physical exam, according to Dr. Adalja—is helpful for decreasing complications from the illness, like corneal abrasion, depression, or social anxiety.

Treatments for Ramsay Hunt Syndrome

Research shows that all patients recover from Ramsay Hunt syndrome to some extent, though some may have more long-term or permanent complications than others. When a patient is young and healthy, full recovery can take several weeks to a few months.

The severity of the facial paralysis is a key factor to how completely a patient will recover, with worse outcomes more commonly affecting people over 50 years old. Although extreme, long-lasting paralysis is rare; synkinesis (unwanted contractions of facial muscles) is more common.

Treatment for Ramsay Hunt syndrome often includes antivirals and corticosteroids. Symptom management through pain medications or those to help lessen symptoms of vertigo may also be prescribed.

Because facial paralysis can render someone unable to close an affected eye, "there is a risk of corneal trauma occurring," said Dr. Adalja, adding that "patients are often prescribed artificial tear drops to keep their eye lubricated."

Although Bieber said his condition is "pretty serious," he is confident that taking time to rest will help him on his recovery journey. "I gotta go get my rest on," he said. "So that I can get my face back to where it's supposed to be."