The way in which severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) manifests clinically is under heavy investigation at the pulmonary and cardiac levels, with the virus significantly dysregulating various processes in these vital organs.
Symptoms include fever, cough, pneumonia, muscle fatigue, gastrointestinal issues, and abdominal pain, often escalating to serious levels.
COVID-19 disease is usually categorized into several levels of severity, ranging from asymptomatic to chronic and when the more severe symptoms mentioned above are restricted to these more critical subsets of patients, PCR tests are required to detect patients who are asymptomatic.
Recently, skin lesions have been described amongst COVID-19 patients, possibly being an indicator of mild infection amongst those previously thought asymptomatic, and additionally may be an indicator of good prognosis, as they less frequently develop in critical cases.
In a review paper recently uploaded to the Journal of Clinical Medicine by Jimenez-Cebrian et al. (May 19th, 2021), the clinical manifestations of COVID-19 in feet, in particular, are reviewed, finding that vascular, dermatological, and neurological symptoms have been widely reported.
Reddish purple nodes have often been observed in young adults and children with COVID-19, and dermatological complications have been found to be more common and serious in diabetic patients.
Through review of the literature the group concludes that 66.7% of these skin lesions are located on the torso, with 19.4% presenting on the hands and feet.
Importantly, almost three-quarters of those with lesions presented this symptom in the seven days prior to positive a COVID-19 test and only 6% in the week following, with the lesions taking on average around ten days to heal. Only in 12.5% of those with lesions did the symptom correspond with subsequent respiratory symptoms, suggesting that they are indicative of a good prognosis.
It is thought that the immune response generated against SARS-CoV-2 can result in significant vascular alterations by activation of clotting pathways and endothelial dysfunction, usually affecting the extremities more severely.
Erythema pernio, known as chilblains, have been frequently reported in younger individuals with mild COVID-19 to the extent that they have earned the moniker “COVID toes.” However, the reason behind their development is not yet apparent.
The group note that amongst the child population, one of the most common vascular manifestations of COVID-19 is Kawasaki disease, which often results in a rash, dry and cracked lips, and red fingers or toes. Exacerbated multisystem inflammatory syndrome and edema in the lower limbs and feet are also seen in infants.
Chilblains were by far the most common observation, however, and were correlated with other vascular conditions that COVID-19 is thought to cause: vasospasms and inflammation in the extremities, unrelated to exposure to cold or moisture.
Some researchers have suggested that such skin manifestations may result from an epidemiological coincidence and not entirely the fault of SARS-CoV-2. However, others have argued that the heterogeneity observed amongst patients and across different areas of the body indicates a common cause.
Some neurological symptoms in the lower limbs and feet have also been noted amongst COVID-19 patients, with Guillain-Barré Syndrome occurring in those aged over 60 in particular.
Before the pandemic, the average age of those suffering from Guillain-Barré Syndrome was 40, and individuals with COVID-19 that have developed this syndrome exhibit more severe manifestations.
Symptoms of this condition include muscle weakness, and thus it presents a high fall risk in the elderly once developed. Unfortunately, rigorous studies into each of these less-discussed aspects of COVID-19 presentation are rare at this time, with the more acute critical symptoms taking precedence.
- Jimenez-Cebrian, A.M.; Castro-Mendez, A.; García-Podadera, B.; Romero-Galisteo, R.; Medina-Alcántara, M.; Garcia-Paya, I.; Páez-Moguer, J.; Córdoba-Fernández, A. Clinical Manifestations of COVID-19 in the Feet: A Review of Reviews. J. Clin. Med. 2021, 10, 2201. https://doi.org/10.3390/jcm10102201, https://www.mdpi.com/2077-0383/10/10/2201/htm