As the coronavirus disease (COVID-19) pandemic grows, more manifestations of the viral infection emerge.
Early in the pandemic, people with COVID-19 reported symptoms of fever, cough, and difficulty breathing. Later, other symptoms were added, such as loss of taste, loss of smell, and mouth lesions in children.
A team of investigators in the Department of Dermatology, Hospital Infantil Universitario Niño Jesús, Madrid, Spain and Dermatologia Pediatrica Association, Bari, Italy, say acral ischemic lesions, similar to chilblains, have been reported across the globe throughout the COVID-19 pandemic.
The overall clinical presentation, course, and outcome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children differs from adults. While urticaria, maculopapular rash, or vesicular rash can happen in people of all ages, chilblains, erythema multiforme (EM), and cutaneous manifestations of pediatric inflammatory, multisystem syndrome temporarily-associated with SARS-CoV-2 (PIMS-TS) are more frequently seen in young patients.
To arrive at the study findings, published in the Journal of Clinical and Experimental Dermatology, the team summarized the current knowledge on cutaneous manifestations of COVID-19 in children after a comprehensive review of articles published in the literature personal experience of dermatologists in Europe.
Chilblain lesions are painful and itchy swelling on the skin, usually seen on the hands and feet, caused by poor skin circulation when exposed to cold.
Chilblain-like lesions tied to COVID-19 are characterized as either an erythematous-edematous or blistering skin lesion affecting the toes and soles. They appear less frequently on the fingers and hands.
The lesions are more common in children, adolescents, and young adults. Most patients have excellent health status and mild symptoms. The recovery in all cases is from four to eight weeks. The team said that though the link between COVID-19 and chilblains is yet to be proven, it seems likely.
Since March 2020, several acral lesions or pernio reports akin to chilblains circulate on social media and Google Trends. Many people searched for keywords like 'chilblains,' 'toes,' 'fingers,' and lesions tied to 'coronavirus' in France.
However, the first published study and case of a possible SARS-CoV-2- associated chilblain-like lesions happened in Italy, followed by some reports of similar cases in Spain and the Middle East.
Patients who reported the lesions tied to COVID-19 were mostly young, confined in their homes due to lockdown orders, and without previous history of the condition.
In Spain, doctors report cases of 'pseudo-chilblains' in 19 percent of 375 patients with skin manifestations of COVID-19. Of these, only one had a previous history of pernio.
Further, the 277 cases reported in France with chilblain-like lesions were mostly confirmed or suspected cases of COVID-19.
Commonly seen in children and adolescents
The lesions are commonly seen in children and teens who are in good health. However, they are rarely seen in children younger than 10 years old.
In 74 to 100 percent of the cases, the lesions appeared on the feet. The multiple and round lesions typically affect the entire toe with a clear demarcation. In some cases, the lesions may become dark-purple with black crusts.
Children and adolescents who develop the lesions are usually asymptomatic, but local pain and itch may happen.
Further, all children and adolescents had a positive health outcome and had no complications. The reported recovery ranged from 12 days to more than eight weeks.
COVID-19 and chilblain lesions
The researchers explained some of the pathogenic mechanisms on how chilblains are related to COVID-19.
First, patients with severe COVID-19 have an impaired interferon (IFN) type I response and increased tumor necrosis factor and interleukin production. The team explained that patients with chilblains manifest a strong IFN-I response, hence, lessening viral replication.
However, early IFN-I response could trigger microangiopathic changes, generating chilblain-like lesions.
Another theory involves the coagulopathy hypothesis. Patients with COVID-19 are at a higher risk of thromboembolism, which can induce acral ischemia development.
Further, patients with neurological signs were found to experience perfusion abnormalities. Microvascular abnormalities have been reported in lung biopsies, hinting at a direct viral effect on vessels. Further, viral proteins were also seen in endothelial cells on the skin from two patients with chilblains.
Lastly, the researchers noted that a change in habits during the pandemic and lockdown could be tied to chilblains. This may be due to walking barefoot at home, lack of physical activity, and stress.