Exfoliating in tattoos, areas of the skin that darkened, urinating after sex and why allergies can appear over time.The office 160º arrives in damn science

We have already reached Friday, damn and damn!And it shows in the face more than one that leaves bridge.With a holiday or not, the Maldita Science Office continues to arrive as every Friday to solve all the doubts that you have raised us.This week we collect your consultations on the use of exfoliants in tattoos, why some of the skin areas darke, if it is advisable to urinate after having sex and why allergies can appear and disappear over time.

Before solving your issues, remember that you can send us to arrive all the questions that occur to you on Twitter, Facebook, Email ([Email Protected]) or our WhatsApp chatbot (+34 644 22 93 19).To mess!

Why can allergies appear and disappear over time?

The reasons behind the appearance of allergic reactions to certain elements in some people and not in others is one of the questions you have asked us this week.Also why sometimes these allergies disappear in some allergic people.It is a complex matter that does not have a clear answer.

Allergy is a defense reaction of the organism against external substances that penetrate the body.The body's immune system recognizes these substances as strange and tries to neutralize them but with some negative effects in doing so.People without allergy also recognize them as strange, but their organism neutralizes them without damaging themselves, through mechanisms called tolerance, explains on their website the Spanish Society of Clinical Immunology, Allergology and Pediatric Astma (SEICAP).

Therefore, the origin of an allergic reaction is therefore not in the agent that produces it, known as allergen, but in the individual himself, the Spanish Society of Allergology and Clinical Immunology (Seaic) stands out on its website (Seaic).Faced with these allergens, the antibodies generated by the organism as defense, usually a type called immunoglobulins E (IgE) act.IGE trigger the release of inflammatory mediators that produce allergic reaction.People without allergy do not usually form IGE in front of allergens, but are defended by other mechanisms, clarify Seicap and Seaic.

And then why appear those allergies?The truth is that today we do not know."Answering questions like why some proteins cause allergies and others not, as well as why they appear and disappear over time are very difficult questions to answer," he clarifies to the damn.It is María Garrido Arandia, biochemistry specialized in plant allergens and molecular bases of the allergic awareness processes in the Center for Biotechnology and Genomic of Plants of the Polytechnic University of Madrid and the National Institute for Agricultural and Food Technology and Technology."It is still a mystery to which there is no clear response," adds Mónica Carreño, a biologist specializing in food allergy to fish and the development of vaccines for food allergies at the CSIC Mariñas Research Institute.

"The allergic reaction occurs because the immune system reacts exaggerated in front of the allergen, a substance that for a large majority of the population is harmless, and identifies it as a danger," he explains damn.It is Sara Benede, Food Technologist and postdoctoral researcher at the Institute for Research in Food Sciences (Cial) of the Autonomous University of Madrid and CSIC.

On the ultimate causes, the biochemistry María Garrido points out that there has to be a genetic background, but the presence of another type of environmental signal as an injury of a tissue, a moment of stress or an imbalance in the microbiota, the microorganisms also seems necessary, the microorganisms, the microorganisms, the microorganismsthat inhabit our bodies, which produces that our body is altered and we recognize that element as a danger.Once that allergen is recognized as something dangerous we already create antibodies in the face of that element that "they will be responsible for their recognition and all the allergic symptomatology,” adds biochemistry, and that will be activated every time we enter into him.

How does the cure of allergies happen?“In many cases, allergies suffered in child and youth age disappear with age.The ‘allergic memory’ disappears or the symptoms are attenuated due to the patient's desensitization to the allergen that has gradually exposed naturally, ”says career.Garrido points out that in allergic mice to which the allergen routinely was administered, he could "re -educate" the immune system and thus get the allergen to become tolerated.The immune system manages to tolerate the allergen by enhancing the regulators T and B lymphocytes (immune system cells) and a change in the type of immune response is achieved, add career.

"Currently almost all immunotherapies are based on the administration of these allergens to the patient so that in the end the patient gets used to him," concludes the biochemistry María Garrido.This type of therapy is commonly known as “allergy vaccines” and are currently marketed to treat asthma, rhinitis, conjunctivitis, hymenoptera bites such as bee and wasp, latex allergy and peach skin, peach,collect the Seicap website.In food allergies, multiple research studies are currently being successfully developed to evaluate the efficacy of food immunotherapy such as milk, egg or peanut, explains Sara Benede.

Is it true that exfoliants spoil tattoos?What to do to take care of them?

Maybe you have encountered a colleague or someone on the Internet who says that exfoliants are advised against tattooed skin because deteriorates them or even erase them.It's true?

Fortunately, this is a myth: exfoliation does not spoil the cured tattoos, since they act in the epidermis, the outer layer of the skin, and do not affect the tattoo ink, which remains in the dermis, just below.“The most exfoliation, more ink is a wrong idea.It cannot be further from reality, ”they explain from Tatring, a portal specialized in information on tattoos and piercings.

According to dermatologist Laura Berbegal, exfoliation consists in helping to regenerate the skin "by removing dead cells from the epidermis".This can be achieved mechanically, "with rough sponges or a mane glove", through chemicals such as creams or acids (glycolic, lactic or salicylic) or combining both."When performing the exfoliation, we help the skin to be softer, we clean impurities and also prepare it to better absorb the active ingredients that we apply later," he concludes.

It is for this reason that from Tatring they recommend including the use of exfoliants as part of the care of a tattoo: "When we get rid of dead cells, we help to appear the new skin and that is why it feels softer and more smooth".

On the other hand, the Paper Crane tattoo study requires that the exfoliating cream will not give problems whenever it is complete.Both the specialized and Berbegal medium clarify that it is also not advisable.

And what is the best to take care of a tattoo?The best thing, in the first place, is to follow the indications of the professional who has done the tattoo, which will offer its advice depending on the tattooed zone (if it is more delicate or more exposed), the sensitivity of the skin of each person or other factorsas allergies or ink used.

Some general recommendations for recent tattoos that point to Vogue the tattoo artist denote it “between three or four times a day with clean hands and with a glycerin soap”, and always keep it clean hydrated to heal correctly.On the contrary, it advises to expose it during the first days "in the sun, to the water of the pool or beach or scratch it".Once it is cured, it is best to take care of hydration, use and defend it from solar radiation with protection.

Why do some areas of the skin (such as knees, elbows, hair removal areas such as armpits or mustache) darken?

In all the scientific offices of Maldita.We insist that we are not health professionals and that the content we create should never be replaced by a diagnosis or medical consultation.And for this doubt that you have sent us it is well embodied: the reasons why these areas of the skin can darken are very wide and only a visit to a dermatologist can determine why this happens, so we cannot offer an answerconcrete.

As we have consulted in Damn.It is the dermatologist Donís Muñoz, "I could not give a diagnosis only knowing those characteristics, I would need to see it in consultation and determine what exactly is".

Muñoz lists some reasons about why these areas of the skin are darkened: it can be acanthosis nigricans, a disorder in which the skin is thickened, dark and velvety in folds and body grooves and is related to genetic syndromes, obsessidad and diabetes;Hyperpigmentation, a disorder caused by the increase in melanin, which is the pigment responsible for our skin tone, hair, eyes and other parts, and that can be caused by solar radiation damage, skin lesions or inflammations;or even "some stain that has adhered to the skin and that is hydrosoluble (that goes with soap and water)"."It seems weird, but I have come to see people in consultation with this last problem," he concludes.

In any case, if anyone has doubts about whether this happens and suspects that it can be a health problem, our recommendation is to go to family medicine appointment and that it is a professional who values it.

Is it advisable to pee after having sex?

In damn.We already explain why it is advisable to urinate after maintaining sex to reduce the risk of bladder inflammation, better known as cystitis.This week you have asked us if, in addition, it can be beneficial for other reasons.The truth is that urinating after practicing sex is a good idea because it not only reduces the possibility of cystitis, also of the rest of urinary infections.

These occur when the bacteria found on the skin or rectum, for example, manage to infect the urinary tract, the system that allows us to get rid of the urine (from the kidneys to the bladder and, finally, outward throughthe urethra).The most common is cystitis.They are more common in women for obvious reasons: “Their urerts are shorter and are closer to the rectum.This makes it easier for bacteria to enter the urinary tract, ”says the Centers for the Control and Prevention of diseases in the United States (CDC).

"To prevent urinary infections, it is recommended to urinate, at most, between 30 and 45 minutes after maintaining relationships," he explains cursed.It is José Gómez Cabezas, Head of the Obstetrics and Gynecology Service of the Valle de los Pedroches Hospital in the Northern Health Area of Córdoba.As the expert adds, there are studies that suggest that "urging after sexual intercourse favors the expulsion of microorganisms and this helps protect vaginal flora and urethra".In fact, health institutions such as CDC recommend urinating to prevent such infections.

However, there are studies, such as this published in 2016 in the American Family Physician scientific journal, who point out that "postcoital urination seems to have little protective effect", although it is "a reasonable and safe practice".

Sexual relations are not the only possible cause of similar infections.There is more likely that these occur if there are changes in vaginal flora (because of menopause or spermicides, for example), during pregnancy, if there are structural problems of the urinary tract (such as the enlarging of the prostate) orIf previous infections have been.Age also influences: they can more easily give both older adults and children.

To try to prevent them, CDC recommends being hydrated;shower instead of bathing;minimize vaginal showers, aerosols and similar products in the genital area and, in the case of women, after going to the bathroom, cleaning backwards and not vice versa.

We have not finished ...

Before saying goodbye, we remind you once more: we are not doctors, we are journalists.You can count on us for everything that is in our hand, of course!But if what you need is a specific diagnosis and or have specific medical doubts, the best option will be that you resort to a healthcare professional who studies the case and recommends the most appropriate solution or treatment.Thank you for reading and good weekend!

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