How to Treat
Post-Inflammatory Hyperpigmentation

June 2021 | 5 Minute Read 

armpit with post-inflammatory hyperpigmentation


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Being a product developer for a deodorant company I get a lot of questions about underarms, especially after I started blogging about all things armpits.  I noticed I was getting numerous emails from customers asking me about why they have dark spots on their underarms. I found that people were insecure about their dark underarms and that they wanted to find a natural but effective way to even out the skin tone in the area.  This inspired me to create products that would help even the skin tone of dark underarms without without any irritating or toxic ingredients. Before I started developing my products I interviewed those that had dark spots on their underarms and started to understand what they were doing that was making the dark spot pigmentation worse. I discovered that the dark spots on their armpits was a result of post-inflammatory hyperpigmentation (PIH). That is why today I’m going to share tips to help you reduce PIH on your underarms and what you can do to treat it.  

What is Post-Inflammatory Hyperpigmentation (PIH)?

woman with post-inflammatory hyperpigmentation

Post-inflammatory hyperpigmentation is when there is discoloration on the skin after the skin experiences an inflammatory wound or trauma. The different patches of color are a result of the over production of melanin.

Melanin is reponsible for giving the skin it’s color. When the skin is healing from a wound, it triggers the melanocytes, the melanin produce cells to increase melanin production. Once the skin is healed the discoloration remains.

Although, everyone roughly has the same amount of melanin producing cells, post-inflammatory hyperpigmentation is common amongst those who have melanin-rich skin.

How Do You Know If You Have Melanin-Rich Skin?

It’s quite simple, if you tan when you’re in the sun then you have melanin-rich skin. Those with melanin-rich skin are more likely to hyperpigment from skin trauma.  If you’re someone who burns from the UV exposure then you’re at less risk for PIH. 

Common Areas People Get
Post-Inflammatory Hyperpigmentation

Dark spots are not just common on the face you can also get them on your underarms, knees, neck, inner thighs, elbows, and outer arms. You can further get dark spots on your body from blemish scarring on your back, chest, and even your buttocks. In addition, darks spots on the body can be caused by bug bites, scratches, or scrapes.  You can make the discoloration much worse and deeper by scratching and itching a bug bite or picking acne. If you want to control the severity of the pigmentation, I suggest finding ways to calm and soothe the skin without further irritation. 

How to Treat Post Inflammatory Hyperpigmentation3

Causes of Post-Inflammatory Hyperpigmentation

They are many things that can trigger an overproduction of melanin and lead to discolouration on the skin. Sometimes PIH can be caused by hormones, fungal and bacterial infections and medications, however common causes of PIH include:  

women with backne without post-inflammatory hyperpigmentation


If you have melanin-rich skin you can get dark spot pigmentation from the sun on your knees and elbows.


Sometimes there are dark spots on the body left behind from a blemish. Many get acne on their body on places like their back, chest, and even their buttocks. It was reported that, beyond the face, 46% of people get acne on the back, 39% get it on their chest, and 17% on other areas on the body.


Hair removal methods like waxing and shaving can cause inflammation and even rashes. The skin in the underarm region is incredibly delicate. It’s equivalent to the skin on your eye lid. So even though your skin may feel fine after shaving, shaving can cause micro-cuts and nicks in the underarm region. 


A common ingredient in natural deodorants is baking soda.  Baking soda is an alkaline substance, and if it mixes with an acid, it can alter the pH levels of your skin. 

women holding waxing strip without post-inflammatory hyperpigmentation

Depending on your skin’s pH, your reaction to baking soda will differ – some will have mild reactions, while others will have more serious and extreme reactions. However regardless of where you fall in the spectrum, using baking soda to treat hyperpigmentation issues is not wise. It’s especially not a wise decision because the underarm skin folds into itself, resulting in rapid product absorption and possible irritation.

How to Minimize
Post-Inflammatory Hyperpigmentation

Chances are you may not know something you’re doing or using is causing inflammation on your armpits. In order to treat post-inflammatory hyperpigmentation, you must first address the inflammation. This means you need to stop doing anything that could be causing your armpits inflammation. Here are some changes you can make to stop the inflammation. 

woman shaving armpit without post-inflammatory hyperigmentation


If you’re going to shave, I recommend shaving at night. Shaving ANY part of your body at night gives your skin time to heal and recover overnight before you expose it to products like deodorant. If you have melanin rich skin use a  shaving oil it will help soften the hair and create a barrier from the razor. This is a much better option than a shave cream or a soap. After shaving use an aloe gel to calm the skin overnight.  Taking these steps to help prevent inflammation and adopting new habits will help save you from dark pigmentation issues in the long term. 


Don’t use deodorants with irritating ingredients like baking soda, alcohol, or high levels of fragrance. If you use antiperspirants the aluminum can be a major irritant for sensitive skins and dermatologist will agree that you need to look for skin calming odor protection. 


The friction and chafing from clothing can also irritate the underarms and cause PIH. Wear light and breathable fabrics (such as cotton, linen, bamboo) or loose fitting items

How To Even Dark Spot Pigmentation Faster

Once you’ve addressed the inflammation you can go ahead and use a topical depigmenting agent to help minimize the dark spots on your underarms. For those who have melanin-rich skin and have this issue I created the first underarm skincare system called the double dose that will help even out the dark spot pigmentation faster. It’s a simple two-step system which includes a deodorant which is something everyone already uses on a daily basis and a body body bar.  By using the products I created together the takesumi bright kojic acid body bar and the takesumi bright niacinamide deodorant  you’re enhancing the effects of the safe and natural ingredients I put in them.


The takesumi bright kojic acid body is a wash-off formula that contains kojic acid and licorice root extract which are anti-inflammatory and skin brightening actives. Use it daily in the shower and lather it for 30 seconds in order to allow the actives to penetrate the skin.  


In order to treat inflammation, the takesumi bright niacinamide deodorant I created contains skin calming ingredients like aloe. To help minimize the dark spots and even the skin tone on your underarms it contains niacinamide and alpha-arbutin. Since it’s a deodorant of course I include probiotic ferment to control odor-causing bacteria. I used alpha-arbutin because it is a safe alternative for hydroquinone an ingredient that is sometimes used in dark spot skincare products.

the takesumi bright double dose set. A set used to treat post-inflammatory hyperpigmentation

Keep in mind that how fast this system works will depend on how dark your pigmentation is, how long you’ve had it and whether you are addressing what is causing the inflammation on your underarms. As with all good things, steady and consistent treatment (and patience!) is your friend to help you reach your desired results. 

Don’t forget every week on my blog The Little Book of Human Discomforts I share clever solutions for seemingly embarrassing skin, body, and hair issues. Consider subscribing below to be the first to know when new content is live!  

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All content found on this website is created for informational purposes only. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this Website. 

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The Little Book of
Human Discomforts


Clean beauty industry maven Mary Futher founded kaia naturals® after spending 20 years working for global beauty companies. Mary now shares her weekly content series, delivering a quick fix, home remedy, or clean beauty product suggestion for a variety of human discomforts that some may find too embarrassing to discuss.

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