The classic triad of symptoms of Covid-19 are fever, cough and dyspnea, but as the pandemic progresses, other symptoms have been recorded in patients with this novel infection. Some rare, but very striking, such as the appearance of skin lesions during the first wave. To investigate this phenomenon, a group of Spanish dermatologists, with the support of the Spanish Academy of Dermatology and Venereology (AEDV), carried out last April the largest study on Covid-19 and skin that has been carried out to date. in the world. Five types of skin manifestations linked to the new coronavirus were established: chilblain-like eruptions in acral areas (19%), vesicular eruptions (9%); urticarial lesions (19%), maculopapular eruptions (47%) and livedo-reticularis or necrosis (6%).
The curious thing is that, seven months later, the doctors have stopped seeing these skin symptoms in Covid patients. “Some authors have doubted that the same virus can have such different effects on the skin, but for me it does not vary much from what this coronavirus does in other organs, with multiple effects”, explains Dr. Alba Català Gonzalo, one of the coordinators of the COVID Piel study. The dermatologist at the Plató Hospital in Barcelona recalls that SARS-CoV-2 needs the ACE2 receptor to enter cells and, depending on the number of receptors of this type that each organ has, whether or not effects are seen on it. cause of this coronavirus.
Dermatologists, who will debate this and other issues from November 19 to 21 at the I AEDV Virtual Autumn 2020 Congress, assure that see far fewer skin symptoms and no chilblains-like manifestations. «During the summer very few cases have been seen, but the incidence of Covid-19 cases has decreased. We will see what happens in this second wave. It is not easy to make the comparison because in March and April 10% of the total SARS-CoV-2 infections were being detected, and now 70% of the cases are detected ”, clarifies Dr. Català Gonzalo. In his opinion, it is to be expected that as cases increase, these skin manifestations will begin to be diagnosed. «In fact, Italian dermatologists are already seeing some cases. However, everything indicates that these manifestations occur in a percentage that is close to the 2% of admitted patients, as we said in our study, a much lower percentage than the one that had been said in the first Italian study on the subject, which placed it at 20% ».
Regarding the chilblains, there was already a debate in April on whether these injuries were due to Covid-19 or to lockdown. “It is true that some authors rule out these chilblains as a result of coronavirus infection, and point as a possible cause to the fact that the children were locked up for weeks and that generated the chilblains. But it is one thing to be locked up at home and another is to be cold or immobile», Explains Dr. Català Gonzalo. But the specialist assures that there are many more dermatologists who defend the link between chilblains and SARS-CoV-2 due to the type of immunity that children have, with an intense response mediated by interferon, which protects them against systemic disease at the same time that it favors the development of pseudo-perniosis (chilblains-type lesions).
Even from the epidemiological point of view, in the opinion of the dermatologist, there is more data in favor of this link because «en all areas where there have been pandemic peaks have seen the same symptoms. However, we cannot deny that we have doubts, although that does not mean that there is no medical basis to explain causation. Furthermore, it is much more difficult to explain this type of injury that occurred in so many people in the same period due to a cause other than Covid-19 ».
Dr. Jorge Romaní de Gabriel, a dermatologist at the Hospital Parc Taulí, in Sabadell (Barcelona), supports this hypothesis: «I believe that in March there were many more cases of Covid-19 that now and that explains that then a percentage of patients developed these skin manifestations and now they are not seen. Although perhaps the cause is that the percentage of the population susceptible to developing these dermatological problems has already been exhausted. The truth is that it is very difficult to understand.
If something characterizes Covid-19, it is precisely the amount of unknowns it generates. Why are there such diverse immune reactions? Why are some tests not positive when it seems that there are Covid parameters? Why has the Covid-19 been primed in global cities? Why has it punished disadvantaged groups more? Dermatologists are not the only questions that still remain unansweredThe same thing happens in other fields, ”says Dr. Cristina Galván Casas, a dermatologist at the University Hospital of Móstoles (Madrid) and one of the promoters of the COVID-Skin study.