Various forms of skin rash are not an unusual part of viral syndromes. Until recently, though, no rash had ever been described as part of COVID-19 infection.
In the last few weeks, however, that appears to have changed. About a fifth of the COVID patients in the Alessandro Manzoni Hospital, in Lecco, in the north of Italy, did recently show skin changes that were not attributable to anything else.1 That’s news.
About half of those patients showed these cutaneous symptoms right away, around the time they felt sick; the rest developed them while they were in the hospital. Their symptoms looked, variously, like red rash, or hives, or in one case, chickenpox. The symptoms were mostly on their trunks. Some people complained of itching. All the symptoms resolved in a few days.
There didn’t seem to be any relationship between onset or severity of these symptoms and the severity of the overall infection, interestingly.
Most important of all, as the dermatologist overseeing these patients observed, the various skin changes were not substantially different from what can happen in other kinds of viral infection.
They can be so similar that a case involving COVID skin changes did indeed fool experienced medical staff in a hospital in Thailand recently.2 Doctors there diagnosed a patient with dengue fever, whose symptoms were exactly right for that. Only upon referral to a bigger hospital, because the patient developed breathing problems, was the right diagnosis made.
Clinicians worldwide can no longer rule out COVID infection whenever they see even ordinary little vascular eruptions that they think might be viral in origin.
Exactly what’s going on, down in the skin, isn’t known yet. We’ll report when we see papers come out about it. COVID rash could be a neurological process, or abnormal coagulation,3 or maybe some complicated immune response. We just don't know.
The important thing to know for now is that the data set about skin and coronavirus has changed. Skin rash, though it doesn’t mean COVID-19 infection by itself, is at least now part of the diagnostic checklist.
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