Your underarms are usually about the same color as the rest of your skin; however, they can darken in some patients. It is benign in most cases. For those who are self-conscious or embarrassed by it, it is best to discuss it with your dermatologist, who can offer some treatment options to help.
Dark underarms result from an increase in the production of melanin by melanocytes in the skin.
It should be evaluated by a doctor to determine if there is an underlying cause.
Genetics, irritation, allergic reactions, and acanthosis nigricans can cause dark underarms.
Treatment of dark underarms includes removing the underlying cause, prescription creams, over-the-counter bleaching creams, peels, lasers, and dermabrasion.
Why do underarms darken?
Melanin production by melanocytes in the skin is responsible for our skin color. Melanocytes are mainly found in the top layer of the skin, called the epidermis. When there is an increased production of melanin, our skin darkens.
What causes dark underarms?
It is critical to discover the reason for your dark underarms, so you can effectively treat it and make sure it is not due to any underlying medical condition. Most times, simple changes can help fade dark underarms. However, some underlying medical conditions that cause dark underarms can have grave consequences if not treated promptly and effectively. It is important to see your doctor if you notice your underarms darkening.
Genetics plays a large role in the development of dark underarms. If dark underarms run in your family, you are susceptible to developing them. Also, darker skin types are at increased risk of getting dark underarms.
One of the most common causes of dark underarms is chronic irritation or friction. Irritation can be caused by using the wrong products, waxing, shaving with a dull razor, shaving daily, or shaving without shaving cream can be irritating. Tight clothes and obesity cause skin friction that leads to irritation and subsequent skin darkening.
In addition to products irritating the underarm skin, some products can also cause allergic reactions. The inflammation from the rash leads to skin darkening, also known as post-inflammatory pigment alteration (PIPA). Patients with sensitive skin are at increased risk.
Bacterial, fungal, and yeast infections in the underarms can also lead to the darkening of the skin in that area. The underarms are a dark, moist place that is conducive to growing microbes. The inflammation from the infection is what causes the skin to darken.
Acanthosis nigricans is a skin condition that causes underarm darkening. It is usually related to an elevation in the body's insulin levels. Elevated insulin levels are also associated with obesity, diabetes, polycystic ovary syndrome, steroid use, and even certain cancers of the gastrointestinal tract.
How are dark underarms treated?
The most effective treatment for dark underarms addresses the underlying cause and fixes it. For this, you will need to initially see your primary care doctor to determine what is causing the skin to darken. After obtaining your medical history and performing a physical exam, the doctor may want to order lab tests to help determine the cause.
If irritation is the cause, you must determine what is irritating your skin and remove it. If you are overweight, try to lose weight through proper diet and exercise. If hair removal is the culprit, use shaving cream and a new sharp razor every time you shave. Also, shave less frequently. Some choose to get laser hair removal instead of shaving or waxing. Also, it is important to use moisturizer after shaving to calm and soothe the area. You should wear only loose-fitted clothing.
If one of your products is causing an allergic reaction, you need to determine which one and stop using it. Your doctor may order patch testing to help determine the culprit. If you have sensitive skin, stick to underarm products that do not contain dyes or fragrances. It is also recommended to do a spot test of the product before using it. Your doctor may prescribe a topical or oral steroid to calm the rash.
If you are prone to infections, using antibacterial soaps in the underarm area and keeping it dry can help prevent infections. Your doctor may take a culture to determine which microbe is causing the infection. Once the culprit is discovered, your doctor will prescribe you a topical or oral medication to eradicate whatever microbe is causing the infection.
If you have acanthosis nigricans, your doctor will need to determine whether it is from obesity, diabetes, medications, or cancer. This may require further testing. Proper diet and exercise can help with obesity and diabetes. If you are diabetic, you will need medications to keep it under control and avoid further complications. If medications are the cause, your doctor may be able to change them to something that will not cause underarm darkening. Finally, if cancer is causing it, the tumor will need to be treated.
If the root cause has been addressed and your underarms are still dark, there are other treatment options to lighten the skin. Topicals and minimally invasive procedures can help. With consistent daily use, prescription and over-the-counter creams can help fade the darkness. Even procedures will take time to lighten the skin. Here are some treatment options to lighten the skin:
- Prescription creams (retinoids, calcipotriene, and hydroquinone)
- Chemical peels
- Over-the-counter bleaching creams containing licorice, kojic acid, and niacinamide
While most cases of dark underarms are benign, some may be caused by an underlying medical condition or cancer. If you have developed dark underarms, have your doctor evaluate them and determine if further testing is needed. Your dermatologist can help you find the correct treatment to fade the dark skin and boost your self-confidence.