Is pink eye a symptom of COVID-19?

Vice President Mike Pence at Wednesday night's presidential debate.
Vice President Mike Pence at Wednesday night's vice presidential debate. (Patrick Semansky / Associated Press)

Is pink eye a symptom of COVID-19?

A lot of people have been wondering this since noticing that Mike Pence’s left eye looked decidedly pink at the vice presidential debate Wednesday night, even though the vice president has said he tested negative for a coronavirus infection.

The short answer is: Pink eye can be caused by COVID-19, but only rarely.

The first thing to know is that conjunctivitis, commonly called pink eye, has many potential causes. The cause for any particular patient cannot be diagnosed properly without knowing the patient’s medical history or conducting an in-person ophthalmic examination, said Dr. Kathryn Colby, chair of the Department of Ophthalmology at New York University's Langone Health.

Even the word "conjunctivitis" is a catchall that simply means redness and inflammation on the surface of the eye.

“It’s not a specific diagnosis,” Colby said. “It’s a description.”

Generally, this inflammation and redness are caused by either a bacterial or viral infection. Among the most common causes of the ailment are the same adenoviruses that can cause a common cold, she said.

“That’s what circulates in dorms or schools or wherever people are in close contact,” Colby said.

COVID-19 has been associated with conjunctivitis, but it is not a common pairing, she said.

She noted that in the early days of the pandemic, a group from China reported seeing a small number of COVID-19 patients who also had conjunctivitis, but the condition was relatively rare.

"Certainly conjunctivitis can happen with any viral disease," said Dr. Colleen Kraft, associate chief medical officer at Emory University Hospital.

However, she said, it would be difficult to know whether Pence had it just by looking at pictures and video of his eye.

"I don’t think that someone who is under enhanced lighting, et cetera, that we can adequately make a judgment on the presence or absence of this sign,” Kraft said.

Colby added that anyone who is experiencing severe symptoms of pink eye, including any loss of vision, should definitely make an appointment to see an eye doctor.

This story originally appeared in Los Angeles Times.