The appearance of dark spots on the neck, armpits or crotch is a condition called black acanthosis. The color change in some areas of our skin usually appears progressively and causes discomfort in people. Specialists explain why this irregular discoloration arises and what to do about it.
Many people present black spots on the neck, armpits or in the crotch. The medical term for this condition is acanthosis nigricans o pigmentaria, and produces a dark, velvety and thick skin on the mentioned parts of the body. He Color change and texture is given slowly and progressively. It has been registered in children, adolescents and adults, especially in people with obesity, according to the Mayo Clinic health portal. Although sometimes it could be confused with dirt, the truth is that the causes are other, according to specialists.
According to EsSalud, the black acanthosis It can also be located, in extreme cases, in other body areassuch as the palms of the hands or feet, the lips, the oral mucosa and other areas. It also affects both women and men and, according to the US National Library of Medicine, usually occurs in people under 40 years of age.
Why do I get dark spots on my neck, armpits or crotch?
In dialogue with La República, Andrés Gómez Noronha, an endocrinologist specializing in hormonal disorders and metabolic, explained that the black acanthosis or pigmentary appears in flexible areas of the body, such as the neck, armpits, elbows, as well as in the crotch and other areas. In addition, he specified that the main cause is the elevation of the hormone insulin in the blood (hiperinsulinemia).
According to the Mayo Clinic, the hiperinsulinemia It refers to the fact that the amount of insulin in our blood is greater than the percentage considered normal. According to the health portal, this situation is due to resistance to this hormone (insulin). That is, the body does not respond adequately to the effects of it.
Being overweight is associated with the appearance of dark spots on the neck, armpits and other parts of the body. Photo: EsSalud
The endocrinologist Gómez Noronha also explained that these dark spots (acanthosis pigmentosa) are also linked to other conditions. “This situation (acanthosis nigricans) is commonly linked to other diseases, such as overweight, obesity, diabetes, polycystic ovary syndrome, among others,” he indicated. The endocrinologist said that it can also be caused by the consumption of certain drugs.
For his part, Guido Paredes Llerena, a doctor specializing in dermatology and a professor at the Universidad Nacional Mayor de San Marcos (UNMSM), explained that it occurs mainly at an early age and when it occurs over 40 years of age it is usually associated with stomach cancer (adenocarcinoma). “When at 40, 45 or 50 years of age you suddenly develop (acanthosis nigricans) without having had it before, you are subject to this association,” he said.
Having dark spots on the neck can be a sign of a disease. Photo: Discussion
How to remove dark spots on the neck, armpits or crotch?
The doctor Guido Paredes Llerena explained that the appearance of the dark spots in different regions of the skin it occurs progressively and has an emotional impact on the patient. That is why the population goes to a doctor to eliminate them.
Andrés Gómez pointed out that the main way to erase them is to identify the cause (obesity, insulin resistance or others) and combat it. For example, if it is overchargedyou will have to modify your diet, improve your lifestyle, exercise regularly and follow the instructions of a doctor.
“The spots are reversible, they do disappear by attacking the main cause. (…) (But) it is not from one day to the next, and it is important that patients know this. This disappearance can be quite progressive, it can last between months and years ; however, if things are done correctly, the spots will gradually disappear,” said the doctor.
Dark spots on the skin can be removed by addressing the underlying medical cause. Photo: Health 180
It is worth noting that, according to the expert, dermatological treatments can help in the elimination process, but the basic treatment will be to mitigate the cause or disease that causes the spots.
“The dermatological part will be able to help, but it is useless to erase them if we still have the underlying problem active, because, in that case, the spots will return anyway,” explained Paredes Llerena. In this line, the dermatologist Guido Paredes Llerena expressed that improvements can be achieved with exfoliating substances applied under the guidance of a specialist doctor and in determined concentrations.
How to prevent dark spots on the neck, armpits or crotch?
The specialists consulted detailed that, in general terms, adequate nutrition, regular physical activity —at least 150 minutes of exercises a week— and sleeping at least 8 hours a day, in the case of adults, can help prevent the onset of black acanthosis.
What tests and exams are done to identify acanthosis nigricans?
According to the US National Library of Medicine, a doctor typically uses three tests to detect black acanthosis if the actual cause of the condition is not known. Also, it is rare that a skin biopsy is necessary.
Blood test to identify the level of insulin or blood sugar X-ray Endoscopy. 
Blood tests help identify what causes acanthosis nigricans in a person. Photo: Fotolia
How long does it take to remove the dark spots on the neck, armpits or crotch?
According to information from the experts consulted and the Johns Hopkins Center, dark spots on the neck, armpits or crotch can disappear after months or years. This is provided that the cause that originates the black acanthosis.
Dark spots in the armpits, neck or crotch can take months or years to disappear. Photo: Your Doctor
How serious is acanthosis negricans?
Acanthosis negricans is not contagious contagious. It is mainly an indicator that the patient is at risk of suffering from diabetes, according to the health organization KidsHealth.
Acanthosis negricans is a sign that the person is at risk of diabetes. Photo: NIH-GOV
What should I not eat if I have acanthosis nigricans?
If you suffer from this skin condition, you should drink water or skim milk instead of sodas, juices, or other sugary drinks. In addition, you must also limit processed, high-fat, and sugary foods.
Why should people remove their makeup before going to sleep?
“People should remove their make-up (before going to sleep) because it prevents skin irritations. (…) If makeup is not removed, pimples, styes, and even expression lines may appear,” dermatologist Guido Paredes explained to La República.
Find out what effects not removing make-up at night has on the skin and how to correctly remove these beauty products from the face. Photo: composition LR/La República/file
According to Paredes, our skin has a component called acid skin mantle, whose function is to protect the skin from bacteria and fungi. Thus, when the aforementioned beauty products remain on our face, their function is altered.
“This (the acid skin mantle) prevents bacteria from growing. And, as the makeup remains, this normal function will not occur in the skin”, according to the doctor.
What would happen to your skin if you don’t remove your makeup?
Dermatologist Fabiana Suero Ramos said that the not removing make-up before going to bed it has several negative effects, such as the appearance of blemishes, expression lines and irritation.
Acne: it causes more bacteria to enter the skin and, consequently, blackheads, pimples or pimples with pus appear.Weaken the tabs: It could increase the possibility of breaking or falling out of the eyelashes, as well as infections.dry skin: this could generate the appearance of expression lines and wrinkles. It can also make enlarged pores more noticeable or accentuate the visibility of certain imperfections.Aging: “The skin is generally renewed every 28 days. And not removing make-up at night causes the dead cells to, let’s say, not ‘go away’ naturally, which is what happens as part of the natural exfoliation process. This will make the skin age faster,” said Dr. Suero Ramos. 
If you don’t remove make-up you could suffer from acne. Photo: The Vanguard
What comes first, removing make-up or washing your face?
Skin specialists recommend removing make-up from your eyes, mouth and the rest of your face with a light product and with gentle circular movements. After that you can wash yourself with water and facial soap. That is, double face wash.
