COVID-19 Infections May Result in Red or Purplish Patches on Fingers and Toes

By Linda Carroll

April 27, 2020

(Reuters Health) - COVID-19-infected patients may develop reddish-purple lesions on their fingers or toes "resembling chilblains disease," doctors from Kuwait report.

They describe two women with a history of recent travel to the UK that called for COVID-19 screening, who developed reddish purple papules on their fingers. Both also tested COVID-19 positive, according to the report in Clinical and Experimental Dermatology.

News organizations around the U.S. have been reporting on similar skin issues recently, dubbing them, "COVID-toes."

"COVID-19 may initially present with cutaneous manifestations," said Dr. Anwar Alramthan, a dermatologist at the Quttainah Medical Center in Kuwait and coauthor of the new report.

"Based on histopathology studies, hyaline thrombus formation in the small vessels may be the underlying cause," Dr. Alramthan said in an email.

The two women described by Dr. Alramthan and his coauthor were aged 27 and 35; they appeared otherwise healthy and both complained of skin rashes.

When Dr. Alramthan and his colleague examined the women, they found "red-purple papules on the dorsal aspect of the fingers bilaterally." One had diffused erythema on her thumb.

After COVID-19 testing confirmed the disease in both women, the physicians performed minimally invasive autopsies of the lungs, blood vessels, skin and other organs, which revealed degeneration and necrosis of parenchymal cells and the formation of hyaline thrombus in the small vessels of the lung as well as other organs.

"This could be the underlying pathology in our cases and could explain the clustering of acral ischemia cases reported in Italy during the timeline of the COVID-19 outbreak," Dr. Alramthan and his coauthor write.

The topic is a hot one among dermatologists these days, said Dr. Laura Ferris, an associate professor of dermatology at the University of Pittsburgh.

"I've seen dermatologists talking about COVID fingers and COVID toes in discussion groups," said Ferris who was not involved with the new report. "And the American Academy of Dermatology is putting together a registry of suspicious cases that are thought to be manifestations of COVID-19. We are all learning as we go."

"This may be the first true peer-reviewed paper that's been published," Ferris said.

No one knows exactly what is causing the skin lesions.

"What we think is causing them is micro thrombi, tiny clots, in the blood vessels," Ferris said. "It looks like a condition called pernio, which can also cause these sort of little inflamed red spots on the toes. With pernio you see them mostly on the feet."

“Many viruses are associated with skin manifestations," said Dr. Amy Paller, chair of dermatology for the Northwestern University Feinberg School of Medicine, who was not associated with the new report. "When you see something this common, you think there might be a relationship. But it could just be a crazy coincidence."

Dr. Paller said she also has seen a lot of discussion among dermatologists, which is where she has been learning about the phenomenon. COVID-fingers and COVID–toes appear to be seen across most age groups, Dr. Paller added.

"Some patients are getting a lot of itching (with the discoloration)," Paller said. "Some get a lot of pain when they are touched. Some look more dusky violet. Some start out red and then turn dusky violet."

Information is all coming in in bits and pieces, Dr. Paller said. "That's why the registries are so important," she added.

SOURCE: Clinical and Experimental Dermatology, online April 17, 2020.