10 Armpit Rash Causes from a Dermatologist
It’s certainly not the most exciting topic, but armpit rashes and armpit irritation are very real—very real, very annoying, and very uncomfortable. There are several possible causes (which we’ll get to in a bit), but certain biological traits don’t help. “The skin in this area is thinner than on most other parts of the body, making it more sensitive and more susceptible to environmental irritation,” explains board-certified dermatologist Teresa Song, MD. It’s also a fold of skin—where skin sits on top of and rubs against other skin—and an area of chronic moisture and friction, creating a perfect environment for bacteria and fungi to grow, she adds.
All of these factors make the area more susceptible to irritation (or intertrigo, a rash in the skin folds, or inflammation). But several different medical conditions can cause armpit rashes. We asked Dr. Song and nationally certified dermatologist Hayley Goldbach to explain the most common causes of armpit rashes. Read on to find out what they told us.
01 of 10
Dermatitis
“Dermatitis simply means that the skin is irritated or inflamed,” Goldbach says. It’s an umbrella term for several types, including atopic dermatitis, seborrheic dermatitis, and allergic contact dermatitis.
The first two of these are relatively rare in the armpits, Goldbach notes. Atopic dermatitis, also known as eczema, isn’t common in the armpits because it’s a naturally moist environment, she explains, and atopic dermatitis is associated with dry skin. Seborrheic dermatitis typically occurs in areas with a high concentration of sebaceous glands, not the armpits, Song adds.
The most likely is allergic contact dermatitis, which is essentially a fancy way of saying you’re truly allergic to an ingredient that came in contact with your skin. It presents as a red, scaly or dotted rash with itching, Song notes, and is usually treated with prescription anti-inflammatory creams. However, she adds, irritant contact dermatitis is more common than a true allergy. So far…
02 of 10
Deodorant rash
According to Song, a deodorant rash is more of an irritant contact dermatitis than a true allergy. In other words, something in the deodorant you use is irritating your skin, but you’re not actually allergic to it. “Ingredients in the deodorant may irritate the sensitive skin in the area, which, combined with the occlusion of the skin folds, can increase permeability and lead to a red, dotted, itchy rash,” she explains.
The first step is to stop using deodorant, then use a topical anti-inflammatory cream. Once the rash clears, it’s best to switch to a fragrance-free, hypoallergenic deodorant, Goldbach says.
03 of 10
Milk Rash
“Milk rash is caused by sweat and heat irritating the affected area, causing the hair follicles and sweat glands to become clogged,” Song says. So it’s understandable that it’s more likely to occur in the summer or in hot, humid conditions.
It usually appears as small, red, clear bumps; the best treatment and prevention options are to ventilate the area and keep the area as dry as possible. (Applying talcum powder can help, Song adds.) It’s also a good idea to change out of sweaty workout clothes as soon as possible.
04 of 10
Folliculitis
Folliculitis is an inflammation of the hair follicles due to an overgrowth of bacteria, Song explains, adding that it can look like red bumps and white pustules. These can also be painful, Goldbach notes, and the condition often requires antibiotics (oral and/or topical, depending on the severity). A visit to a dermatologist is definitely necessary.
05 of 10
Inverse psoriasis
Psoriasis is an immune-mediated inflammatory skin disease; inverse psoriasis is just a form that usually appears in the folds of the skin, Song says. But it also looks a little different than normal psoriasis. “Because of the moist environment, it looks like well-defined red patches without the surface scaling that occurs with psoriasis elsewhere on the body,” she explains.
Goldbach adds that this is another condition where you absolutely need to see a dermatologist, as treatment options range from topical therapies to biologic medications.
06 of 10
Tingles
Tingles is a fungal infection that can develop from moisture retention in the armpits, Goldbach explains. Song tells us that it presents very specifically—namely, well-defined, ring-shaped patches with red edges. Treatment usually involves the use of a topical antifungal.
07 of 10
Candida
This is a different type of fungal infection, but it’s caused by Candida. (AKA: It’s the yeast infection in your armpits.) It looks like red patches with small red lesions nearby, Song says.
“However, sometimes it can look like a severe rash that doesn’t respond to typical treatments. In that case, you should see a doctor,” Goldbach adds. She notes that topical antifungals are usually used, along with powders or tablets, but it also helps to keep the area as clean and dry as possible.
08 of 10
Cancer Treatments
“Cancer treatments can sometimes cause a rash called erythema chemotoxicum,” Song explains. It can affect the hands, feet, and skin folds (including the armpits) and appear as red, tender patches and blisters. Anti-inflammatory creams are a common treatment, and in severe cases, oral steroids may be needed, she adds.
09
Total 10
Acne inversa
Also known as hidradenitis, acne inversa is a chronic inflammatory disease that affects hair follicles. It can occur in all folds of the skin and manifests as recurring boils, scars, and the formation of subcutaneous sinuses, Song said. Both dermatologists we spoke to said it is a very difficult condition to treat and definitely requires the help of a dermatologist.
10
Total 10
Erythrasma
According to Goldbach, erythrasma is “a bacterial infection that specifically affects the armpits,” Song adds, and it manifests as red patches of hyper- or hypo-pigmentation that are accompanied by mild itching, noting that it can be treated with topical antibacterial washes and creams.
Many medical conditions can cause armpit rashes. So if you experience discomfort in this area, it’s best to make an appointment with your dermatologist to find out the exact cause and the best treatment. Beyond that, keeping your underarms clean and dry, as well as using fragrance-free deodorant, are good tips that help on all fronts.
