Coronavirus: ‘Chilblains’ indicate unique group without symptoms, say GPs

Doctors raise alarm there may be significant numbers of undetected coronavirus cases after unusual increases in chilblain patients.

A person with chilblained toes. Picture: Wikipedia

Doctors are raising concerns that there may be significant numbers of undetected COVID-19 cases in the community after highly unusual increases in patients­ presenting with apparent chilblains.

Chilblains are a circulatory disorder that creates inflammation of small blood vessels in the skin, commonly in the feet. Inter­nat­ion­al research has linked corona­virus with chilblain-like symp­toms, with the rashes being dubbed “COVID toe”. Corona­virus-infected patients have been observed to develop reddish-­purple lesions on their fingers and toes that resemble chilblains.

Chilblains are uncommon, but GPs from across the country are reporting an increasing number of patients presenting with the condition. They believe the chilblains in many cases are in fact COVID toe, despite many of the patients testing negative.

Sydney GP Bruce Solomon said he had seen three cases of apparen­t chilblains in past weeks. Discussing the issue with GP Anna Lindsay, who had seen four recent cases, they became convinced their patients­ had COVID toe.

“I would probably usually see a case of chilblains once every five to 10 years, but over the last few weeks I’ve seen three cases,” Dr Solomon said. “Other doctors are seeing exactly the same thing. Pod­iatrists in Melbourne are also very busy at the moment with chilblains, and some of them are now working out that this is COVID toe.

“So you have a sub-group of literally­ hundreds of people with chilblains who I believe have COVID toe and, if that’s true, these people become a really interesting sub-group because they have theoretically picked up COVID two to three weeks earlier, not passed it to friends and family, not passed it around the school, presented to the GP with vascul­itis, and the GP has tested and said ‘you don’t have COVID’.

“Hypothetically, these people should be studied to why they have picked up COVID, developed the vasculitis, but not been unwell.”

According to international research­ that has reported on COVID toe in scientific journals, people with the condition are often asymptomatic or have mild cases of coronavirus. In all three of Dr Solomon’s patients­ who presented with chilblains, COVID-19 tests were carried­ out and were negative. But he nevertheless believes they likely had COVID-19.

“My belief is that the tests that we have, the nasal swabs and the blood tests, are not sensitive enough to pick up all cases and that possibly these people had the infection three weeks before they presented to the doctor,’’ he said.

“If these people with chilblains actually had COVID toe, then they’re going around undiagnosed and not passing it on.”

When the publication Australian Doctor this week reported Dr Solomon’s observations about an unusual number of patients presenting with chilblains, many GPs responded with similar reports.

Health authorities said RT-PCR testing for COVID-19 had an accuracy rate of about 70 per cent.