The COVID-19 infection, which had originated in Wuhan, China, late last year, had primarily emerged as a respiratory infection caused by the SARS-CoV-2 virus. However, after spreading to almost every part of the world and infecting over 13.8 million people, more and more symptoms unrelated to a respiratory infection have emerged in recent months.
Signs of fever, cough and shortness of breath are known to be some of the more established symptoms of the new coronavirus infection, but recent assessment of patients admitted to hospitals have also shown symptoms of many other kinds.
After a study conducted by the King's College London established that skin rashes should also be added to the list of infections, a new study published in JAMA Dermatology, a peer-reviewed journal, has shown that patients who develop skin rashes as a result of contracting the viral infection also end up with enanthem, or rashes in the mouth.
While skin rashes have earlier led doctors to think the infection could be due to some other illness, the presence of enanthems is said to be a confirmation of the patient carrying the SARS-CoV-2 virus.
Read more: Skin rashes also a symptom of COVID-19
Enanthem are oral cavity lesions, rashes or small spots on the mucous membranes and appear inside the body, which is characteristic of viral infections such as measles, chickenpox or hand, foot and mouth disease.
By contrast, exanthem are lesions or rashes that appear on the outside of the skin. They may occur due to acute infections or as a reaction to certain drugs or medications.
COVID-19 patients have already presented with skin rashes of different kinds that include hives, vesicles similar to chickenpox as well as a peculiar redness of the skin known as erythematous rashes.
The enanthem that appeared on the mouths of the patients were classified into different categories, with erythema multiforme (redness with many shapes resembling a bulls-eye) observed among three out of the six patients, while purpuric periflexural (dark, bluish spots) appeared on two of them. Another patient was seen with papulovesicular (breaking out of papules and vesicles in the rash).
One of the reasons why lesions in the oral cavity have not been as widely reported as other visible symptoms could be the site of the rashes breaking out, as they may have gone unnoticed upon clinical examination.