Despite all the love and care I put into my skin, I never gave much thought about my armpits — until, in February 2026, my underarm skin suddenly became itchy and irritated with a rough texture.

As a longtime beauty editor, I treated my face and body to the best products and treatments, but my underarm routine was pretty much nonexistent. 

I’d give the area a rough quick shave, swipe on deodorant and call it a day. But my big mistake was that I never checked if the razor I used was fresh or if the deodorant I had lying around was actually expired. 

Sound like no big deal? I thought so too — until I paid for it.

At first, I ignored my symptoms, hoping it would go away. But the inflammation only got worse. I finally paid a visit to my dermatologist, who immediately recognized the rash as underarm dermatitis, an unpleasant — although highly treatable — skin condition.

And she schooled me on the incredibly common mistakes that can cause this, which many of us make.

What is underarm dermatitis? 

According to Dr. Chelsea Hoffman, MD, a board-certified dermatologist at Hudson Dermatology and Laser Surgery in New York City, dermatitis is a generic term for skin inflammation. 

The most common form is contact dermatitis, which can occur in your underarms. This can be broken down into two categories: irritant dermatitis and allergic dermatitis. 

“Irritant dermatitis comes from a substance touching your skin, which is causing an irritant reaction, or a rash,” says Dr. Hoffman. 

“If someone’s putting an active ingredient under there, such as a retinoid, which some people try to do for pigment, that could cause irritant dermatitis. But even just sweat alone can be irritating to people.” 

While irritant dermatitis appears quickly, allergic contact dermatitis is typically delayed. As the name implies, allergic dermatitis is an immune response to a specific allergen in your environment. 

“The most common causes are certain ingredients and additives, like preservatives or fragrances in deodorant,” says Dr. Hoffman. 

The repercussions

My dermatitis was likely caused by an old razor or expired deodorant (both of which I had been using at the time), which then developed into atopic dermatitis, also known as chronic eczema. 

Since my underarms went untreated for a few months, my condition worsened, creating a chronic condition that left my underarm skin thick and scaly, with leathery lines due to dryness. Additionally, the rash caused discoloration, leaving me with darkened armpits. 

Redness and itchiness are common after you shave, but should be temporary. If irritation persists, Dr. Hoffman recommends making an appointment with your dermatologist to identify the cause. 

“There’s other conditions that can happen too. It’s more rare, but you can get fungal infections in your underarms. Yeast can play a role. There’s all these other microbiome, pathogen aspects because they thrive in that moist environment.”

Treating underarm dermatitis

At my doctor’s orders, I stopped shaving and applying deodorant to my underarms for nearly three months. I have thin hair and my body odor isn’t noticeably strong, but I still felt very self conscious. 

“We treat underarm dermatitis by reducing irritation, so you want to try to minimize shaving or waxing for that time,” says Dr. Hoffman. 

“Anything that’s going to compromise the barrier, you want to avoid.” This is also why it’s so important to use a fresh and clean razor: “Shaving basically kind of takes off the top of your skin,” she adds.

I was prescribed a topical steroid to bring down the irritation and was told to use a lightweight and un-fragranced moisturizer to heal my damaged skin barrier. At first, moisturizing my armpits felt odd, but then I realized: I never skip my face or body — why should my underarms be any different? 

How to care for your underarms and what to avoid

According to Lauren Lovelady, founder of the body care brand Each & Every, the skin in our armpit is delicate and vulnerable, especially during the summertime, which calls for some TLC. 

“I don’t want to say we abuse our underarms, but we do tend to put a little bit more stress on it than other areas of our skin by shaving and applying products,” she says. “That skin is sensitive and can get really dry, so it is really important to keep it moisturized. Look for products that have ceramides or lactic acids, things that you would apply to your body to keep it moisturized.” 

Some of Dr. Hoffman’s favorite lotions for the underarm include Person & Covey DML Moisturizing Lotion or Vanicream Moisturizing Lotion, which are thin and absorb quickly. 

When it comes to the natural versus aluminum deodorant debate, Dr. Hoffman says the choice is ultimately up to your preference. However, if you use natural deodorant, be aware that sweat is an irritant. 

If you’re a heavy sweater and experiencing dermatitis, it might be worth switching to aluminum deodorant, which uses antiperspirants to block glands and keep you dry. 

Additionally natural deodorant typically contains baking soda as its bacteria-killing agent, which can also cause inflammation. 

“Baking soda raises the pH of your skin,” says Lovelady. “Your is naturally acidic and sits at about a pH of 4.5 to 6.5. And baking soda is very alkaline, so it’s about a 9. When you apply deodorant with baking soda, it raises the pH of your skin above its normal levels.”

If you find yourself having frequent reactions, Dr. Hoffman recommends conducting an allergy test with your doctor. “If it continues to become a problem, we’ll do patch testing on the back looking for what you might be specifically allergic to,” she says. 

To make identifying triggers easier, Lovelady includes both the regulated name and common household of ingredients for full transparency. “We disclose all the ingredients on the package so you know exactly what you’re putting on your skin. We even disclose allergens in case you have a specific ingredient that you’re sensitive to.” 

The aftermath

After a few months of applying topical steroids and moisturizing my underarm area with La Roche Posay Lipikar Daily Repair Moisturizing Body Lotion, my armpits have returned mostly back to normal.

I still have discoloration, which my dermatologist said will take some time to fade away. I’ve even started shaving and applying deodorant again (Each & Every Aprés Sea smells incredible and gives me zero issues) so I finally feel free to lift up my arms.