The claim: Pink eye is a possible symptom of COVID-19

According to several articles shared on social media, pink eye has been found to be a symptom in some coronavirus patients.

One such article by HealthDay News posted on the WebMD website has a headline that reads, “ ‘Pink Eye’ often a symptom of COVID-19, and infection via tears possible.” The article says a study by Chinese researchers that examined 38 patients with COVID-19 and found 12 also had pink eye. In two of the patients, the virus was found in eye fluids.

The claim has appeared on several other news websites, many citing the above study and guidance by the American Academy of Ophthalmology that pink eye could be a symptom.

Pink eye and COVID-19

COVID-19, the respiratory disease caused by the novel coronavirus, has several known symptoms, including fever, cough, fatigue and shortness of breath, according to the Centers for Disease Control and Prevention. Symptoms may appear two to 14 days after a person’s exposure to the virus.

Conjunctivitis, or “pink eye,” is not listed by the CDC or the World Health Organization as a major symptom.

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According to the CDC, pink eye is commonly caused by bacteria, allergens, irritants or viruses, including some respiratory viruses. Symptoms can include a pink or red color in the white of the eye, increased tears, itching, discharge, crusting of the eyelids or lashes and swelling of the "conjunctiva," the mucous membrane covering the inside of the eyelid and white of the eyeball.

The study cited in the article posted by WebMD was published March 31 in the Journal of the American Medical Association. It found that of 38 Chinese patients with COVID-19 in Hubei province, 12 (32%) had "ocular manifestations consistent with conjunctivitis." Those symptoms frequently occurred in the patients who had the more severe COVID-19 symptoms, the study said. Of the 12, two tested positive for coronavirus in conjunctival swabs.

Though there's limited research on the topic, other available studies don't show a rate that's nearly that high. One study in the Journal of Medical Virology published in late February found one out of a group of 30 COVID-19 patients studied in China had conjunctivitis.

A study in The New England Journal of Medicine found conjunctivitis in just nine of 1,099 COVID-19 patients in China. None of those patients was shown to have seen ophthalmologists or had tears sampled.

Dr. Sonal Tuli, spokesperson for the American Academy of Ophthalmology, said the science about a connection is "very tentative."

"There is some evidence that there is conjunctivitis, and you might be shedding virus in your tears," she said. "But it's extremely rare is what we think at this point."

The American Academy of Ophthalmology classifies conjunctivitis as an uncommon symptom of COVID-19, possibly present in 1% to 3% of those infected.

On its website, the AAO disputes that the first paper shows 32% of those studied had conjunctivitis, since some of the symptoms listed in the study could have been caused by other factors.

Tuli said the medical community needs larger, more controlled studies to fully show a connection.

"Unless we have some sort of a study with a large group of people at different stages of coronavirus and looking at the tear films, I don’t know if we can actually make a very definitive decision as to whether this is something that we need to be worried about at this point or not," she said.

On CNN last month, a registered nurse at the Life Care Center in Kirkland, Washington, said reddening around the eyes was a common sign in people who became sick with the virus.

“It’s something that I witnessed in all of them (the patients),” she told CNN. “They have, like … allergy eyes. The white part of the eye is not red. It’s more like they have red eye shadow on the outside of their eyes.”

Tuli said the CNN report about the nurse noticing red around the eyes isn't a symptom consistent with pink eye itself.

Our ruling: True

We rate the possibility of pink eye as a COVID-19 symptom as true according to available studies, but more research is needed to concretely show the connection.

Available research points to pink-eye-related symptoms occurring rarely in COVID-19 patients – potentially only in 1% or fewer.

Though available studies prompted the AAO to classify pink eye as a symptom, the group's spokeswoman said the link is tentative and, like many other aspects of the disease, will need further research.

Neither the CDC nor WHO lists conjunctivitis among the main symptoms of COVID-19.

For people experiencing only pink eye and no other COVID-19 symptoms such as a fever, dry cough or shortness of breath, it's probably no reason for panic. The AAO's website advises people to remember it's allergy season, and viral pink eye is common on its own.

Our fact-check sources:

Ian Richardson covers the Iowa Statehouse for the Des Moines Register. Reach him at irichardson@registermedia.com, at 515-284-8254, or on Twitter at @DMRIanR.