While many of us are on constant alert for a cough or fever that might suggest we’ve caught COVID-19, our skin may be the first place the virus makes itself known.

Skin rashes, particularly on the hands and feet, are often the first sign of coronavirus infection in people with no other symptoms of the illness, according to recent research.

Published in the American Journal of Clinical Dermatology, the evidence-based review included one noteworthy study suggesting skin symptoms affect up to one in five COVID-19 patients.

“Physicians should use this information to identify patients with COVID-19 who have no other symptoms,” said study author Daniel Gould, MD, PhD. He’s an attending physician in the Division of Plastic and Reconstructive Surgery at Keck School of Medicine of the University of Southern California in Los Angeles.

“If a patient says they’ve got a strange rash, a doctor’s first question should be, ‘Have you been in contact with anyone with COVID-19?’” Dr. Gould told Medical Daily. “Physicians should also use the information to be more aggressive in testing for the virus.”

Rashes don’t always appear first

Dr. Gould and his colleagues combed through a research database on a single day in May 2020 for studies that included patients with both suspected or confirmed COVID-19 and skin symptoms. They found nearly three dozen papers, 996 patients in total, though only four studies involved larger groups.

Various types of skin rashes were observed in coronavirus patients, ranging from small blisters and hives, to pink and red blotches, to small, itchy bumps marked by red and purple spots. This latter rash was the most frequent type identified in COVID patients, affecting more than 40%, and it usually showed up in young adults who experienced other virus symptoms first.

Dr. Gould said the coronavirus might provoke skin symptoms in two main ways: either because of inflammatory chemicals generated by the immune system to fight the virus, or tiny blood clots resulting from the virus.

“I wouldn’t say the rash per se is dangerous, just a herald sign we need to watch for,” he explained. “Often the complaints related to COVID-19 are so variable, ranging from loss of sense of smell to a raging fever and extreme illness. But if a primary care physician or pediatrician sees rashes, they need to know this could be another manifestation of the virus.”

COVID outcomes may be tied to rash type

Esther Freeman, MD, PhD, director of Global Health Dermatology at Massachusetts General Hospital in Boston, said Dr. Gould’s research findings are similar to those observed in the International Dermatology COVID-19 Registry. Since April, the database has amassed more than 1,000 cases from 41 countries of COVID-19 patients with skin symptoms.

Dr. Freeman, also the director and principal investigator of the international registry, published recent research that adds important insight about which COVID-related skin rashes point to better or worse outcomes. Red and purple bumps on the fingers and feet, informally known as “COVID toes,” generally point to milder disease, while a blotchy red or blue net-like rash often means more severe COVID, the study suggested.

“In most cases, the rash is coming after the cough or fever,” Dr. Freeman explained. “But it is important to highlight that there are some patients where their very first presenting sign of COVID-19 is the rash. If we have patients come in with new-onset hives and no explanation for why, we COVID test them to make sure we’re not missing COVID.”

Pandemic stress can hit the skin

Meanwhile, even those who haven’t contracted COVID-19 aren’t necessarily immune from the pandemic’s skin effects. The stress of the global health crisis can cause us to produce more of the inflammatory hormone cortisol, Dr. Gould noted. This can lead to acne breakouts, hives or worsening cases of chronic skin conditions, such as psoriasis and eczema.

With the average wait time to secure a dermatology appointment stretching to 32 days – increasing 46% between 2009 and 2017 – relying on your primary care doctor is a good idea if you’re dealing with any puzzling or bothersome skin problems, Dr. Gould said.

“We see a lot of patients coming in now and saying their skin is horrible,” he said. “Patients should always fall back on their primary care provider. Most of the time, they’re really good at identifying skin problems and treating many of those conditions.”

Maureen Salamon writes about health and medicine for websites, magazines and hospitals such as Medscape, St. Jude Children’s Research Hospital, Weill Cornell Medicine and others.