The reasons why post-covid hair loss is such a common problem are still not entirely clear, but science already points to some possible relationships between the virus and the intense elimination of hair, a condition whereby one in four infected by Sars-CoV -2 experience.
“We know that viral infections, in general, are capable of promoting hair loss, a condition known as acute telogen effluvium”, says dermatologist Jaqueline Zmijevski, from Corumbá, in Mato Grosso do Sul, a member of the SBLMC (Brazilian Society of Laser in Medicine and Surgery).
In addition to covid-19, according to the SBD (Brazilian Society of Dermatology), other conditions that can trigger telogen effluvium are fever, acute infection, sinusitis, pneumonia, flu, very restrictive diets, metabolic or infectious diseases, surgeries, especially bariatric, due to blood loss and metabolic stress, in addition to emotional stress.
In the case of covid-19, when the patient realizes that the condition persists without improvement even after a period of four months after infection, it is essential to undergo an investigation.
“What we have observed is that many patients who come to the clinic with this acute problem already have a basic problem, such as alopecia areata or androgenetic alopecia, which had gone unnoticed before”, explains physician Fabiane Brenner, from Curitiba, coordinator of the Department of Hair and Nails at SBD.
Some scientific works indicate that the viral infection may have served as a trigger for the manifestation of other conditions, but there is still not enough robust evidence, according to the doctors interviewed by BBC News Brasil, to confirm the relationship.
Effluvium, considered the main reason for hair loss after Covid-19 infection, is self-limiting, that is, it has a predetermined duration of two to four months, if there is no other associated disease. In theory, no treatment would be needed.
“But in practice we know that the fall is very uncomfortable and causes apprehension in patients, who have the feeling that they will be bald. There are treatment options that can help in this acute phase triggered by covid-19 and also for those who have underlying problems”, he indicates. Vivien Yamada, a dermatologist from São Paulo, also specialized by SBD.
Before starting a treatment, it is necessary to know the cause of the hair loss to better direct the approach to each person.
Using a test called a trichoscope, the specialist examines the scalp through a zoom lens in a dermatoscope and checks the health of the hair follicles.
“It is also possible to do what we call a traction test. We hold about 50 wires and apply some pressure. If more than three fall out, it is indicative of effluvium”, points out Yamada.
The healthcare professional may also order tests to check levels of iron, vitamin B12, thyroid hormones, and others that could be indicative of adjacent conditions.
An important reminder left by doctors is that you should not start using any medication or therapy on your own.
“Minoxidil, a drug widely used in these cases, can cause a decrease in blood pressure, and therefore is contraindicated for patients with conditions such as heart or valve failure and arrhythmia. It is necessary for people with these comorbidities to undergo evaluation with a cardiologist “, exemplifies Brenner.
Topical and oral treatments
Minoxidil, cited by the coordinator of the SBD, is the main drug prescribed for those who suffer from hair loss. It works as a stimulant for the growth of new follicles, shortening hair recovery time.
It can be used topically, directly on the scalp, or taken in pill form.
“These are approaches that help, but even so, it is necessary to explain the process to the patient, since the middle of the hair loss crisis causes anxiety. He needs to understand the cycle, knowing that the improvement may not be so fast” , says Brenner.
Anti-inflammatory drugs and corticosteroids, which fight the damage caused by viral infections, can also be prescribed, but their effectiveness depends a lot on each patient’s condition, and therefore, it is not recommended to use them without medical advice.
Another widely prescribed option is biotin, a supplement that improves the quality of the hair. But although it can be used as a complementary treatment, doctors warn that there is no scientific evidence that the substance helps in cases of effluvium.
Exsynutriment also has a similar function. “It is a source of silicon, which ‘pulls’ water to where we have cretin, that is, it hydrates the skin and hair. It is a very nice supplement, but there is no evidence of its efficiency to combat effluvium”, explains Yamada. .
The microinfusion of medicines on the scalp can also be used for intense hair loss. The procedure is often used as a supplement.
“We use microneedles immersed in medicines that make small holes of controlled depth, causing the assets to be delivered in an optimized, precise and uniform way. In addition, the needles themselves promote an increase in local vascularization and release of substances that activate cell multiplication, which also favors hair growth”, points out Zmijevski.
Intradermotherapy, also known as mesotherapy, and microneedling use this same principle.
The mixture of substances is particular to each case, but it can take anti-inflammatory drugs, minoxidil, vitamins and others.
In cases where alopecia is found, the infiltrations may contain a hormone blocker such as finestertide, which inhibits the action of the hormone that acts on the condition.
Although it is not a consensus among all doctors, specialist Jaqueline Zmijevski comments that the low-frequency laser is also an option to help in the growth of new hairs.
“It works by improving local vascularization and consequent supply of nutrients, reduces the inflammatory process around the follicle, minimizing hair loss, dandruff, itching and scaling, in addition to stimulating mitochondria, cellular organelles responsible for providing energy to the follicle, optimizing the production of new yarns.”
Text originally published in https://www.bbc.com/portuguese/geral-62383439