A rash inside the mouth could be a symptom of COVID-19, according to a small study. Doctors in Spain examined the mouths of 21 COVID-19 patients who had rashes on their skin to see if they had enanthem, or a rash inside the body on the mucous membrane.
The patients at Ramon y Cajal University Hospital in the Spanish capital of Madrid were diagnosed with the coronavirus which causes COVID-19, and had dermatology appointments between March 30 to April 8, 2020. The findings were published as a research letter in the journal JAMA Dermatology.
The researchers found six (29 percent) of the patients had some form of enanthem in their mouths. These patients were aged between 40 to 69-years-old, and four (66 percent) were women. On average, it took around 12 days for the patients to develop a rash on their mucous membrane after they showed known COVID-19 symptoms. This ranged from fewer than two days to 24. Most of the six patients (83 percent) had petechiae, or small purple, red, or brown spots in their oral cavities.
Dr. Michele Green of Lenox Hill Hospital in New York City who did not work on the paper told Health Day enanthem "is very common in patients with viral infections like chickenpox and hand, foot and mouth disease. It is characteristic of many viral rashes to affect mucous membranes."
Past research into COVID-19 has found a link between the disease and skin rashes, the team said. But it is unclear whether these are caused by the viral infection or drugs given to patients. According to the authors, "an important clue" to distinguish between the two is a rash inside the mouth. But due to safety concerns around the spread of the virus, many patients suspected or known to have COVID-19 do not have their mouths examined.
Understanding the cause of the skin rashes "is challenging," the authors said. A person having enanthem "is a strong clue" that they are linked to the viral infection rather than the patient's reaction to certain drugs, they said.
The team said the research letter described preliminary observations, and the findings were limited by the small number of patients and the lack of a control group.
U.K.-based consultant dermatologist Dr. Veronique Bataille who did not work on the study told Newsweek via email: "this is something we have observed and COVID-19 can affect mucosa including eyes, mouth and rarely genitals. The symptoms can be quite subtle but patients reports a sore mouth and/or sore lips for a few days."
Bataille recommended individuals with these symptoms "request a test as soon as possible" and self-isolate, particularly if they have no previous history of inflammation in the mouth or lips.
Since COVID-19 first emerged late last year, evidence has built that the disease does not only cause the most widely known symptoms of a dry cough, fever, and shortness breath. The loss of a sense of smell or taste is among symptoms to have been attributed to COVID-19 later in the pandemic.
According to the U.S. Centers for Disease Control and Prevention website, COVID-19 has a "wide range of symptoms" which may appear two to 14 days after a person is infected. These include fever, cough, shortness of breath, the loss of smell and taste, fatigue, muscle or body aches, headache, sore throat, congestion or runny nose, nausea and vomiting, and diarrhea. "This list does not include all possible symptoms" the CDC said on its website.
Dr. Tony Bewley of the British Association of Dermatologists who also did not work on the paper told Newsweek:"This study is clinically useful, in that it reminds dermatology healthcare professionals to look in the mouth of patients with skin rashes thought to be related to COVID-19, as that can help to distinguish between viral related skin rashes and those related to medication reactions."
Bewley said: "Due to the small sample size, and the fact that COVID-19 is a new disease, it would be good to see more research into this topic."
This article has been updated with comment from Veronique Bataille and Tony Bewley.
https://www.newsweek.com/covid-19-symptoms-mouth-rash-study-1518972