Allergic skin reactions in the underarm and armpit area: deodorants and other triggers
Updated: Mar 3
If your dermatologist or allergist has diagnosed you with allergic reactions of the underarm area, the information below will provide more guidance on what items to avoid.
Natural deodorants such as Tom's of Maine may trigger allergic skin reactions in the armpit/ underarm area
There are many causes for rashes in the underarm area. Some rashes may be due to infection, such as a yeast infection of the skin. For other persons, the skin of this area may become irritated by heat, sweating, and rubbing of the skin. Sometimes these rashes are due to certain inflammatory skin conditions. Diagnosis will require an exam of the area, and may even require further testing. If your doctor has diagnosed you with dermatitis of the underarm area (which is a specific type of skin inflammation), the recommendations below will help.
Since the skin of the underarm area is exposed to sweat and rubbing, it can become irritated. This is known as irritant dermatitis. In other cases, people can become allergic to items or substances that contact this area.
What is allergic contact dermatitis (ACD)? Why is it so hard to diagnose?
ACD is a type of allergic reaction. In this type of allergy, a substance contacts the skin, and later results in a rash. The rash from poison ivy is one example. The rash classically occurs 2-3 days later, but it may happen just a few hours later, or one week later. This delay is what makes ACD so hard to figure out.
Once the rash occurs, it may last for weeks, and sometimes up to 8 weeks. People may stop using the triggering product for 1-2 weeks, but that’s usually not long enough to see results.
What substances trigger ACD of the underarm area?
1. Products that contact the skin directly, such as deodorant.
2. Items that contact the skin, such as fragranced laundry detergent or laundry additives.
3. Chemicals or dyes used in clothing. 4. Topical medications, including some OTC or Rx creams, such as Neosporin or Polysporin or tea tree oil.
What are some of the most common substances that trigger ACD of the underarm area? How can I avoid them?
1. Deodorant. For rashes that are in the armpit itself [known in medical terms as the axillary vault], a major concern is deodorant. The most common culprits are fragrance additives in the deodorant. The options listed below are free of fragrance additives. It's a little-known fact that products that are labeled as fragrance-free may still legally contain some fragrance additives. This is why we are very specific when providing product recommendations. Propylene glycol is another chemical used in many deodorants, and this may serve as a trigger also.
Even "all-natural" deodorants are potential triggers for allergic reactions in the underarm area, due to their natural fragrance additives
2. Laundry detergent. For rashes that are in the axillary vault and/or extending to the surrounding areas, a common trigger is laundry detergent or additives. Fragrance additives in laundry detergents are a common trigger, and this includes both natural fragrances and synthetic fragrance additives. Even organic detergents and baby detergents may contain fragrance additives. Dryer sheets and fabric softeners may also serve as triggers. I have also seen cases due to fragrance additives [such as Unstoppables], which are designed to last in clothing through multiple washes.
3. Clothing itself. While many people are aware that laundry detergent can be a problem, it's less well-known that items of clothing themselves may trigger allergic reactions. This may be due to the dyes that are used to color the clothing, or may be due to other chemicals [formaldehyde finishes] that are sometimes added to clothing to make it wrinkle-free. While you should always wash clothing before wearing, some of these chemicals stay in clothing despite washing. I've seen more reactions in recent years from some of the dark clothing dyes that are used in synthetic materials, such as work-out clothing. The most common triggers are blue dyes, which may be found in black or blue or red or other colors of dark clothing.
The dyes in clothing are another potential cause of allergic skin reactions in the underarm area. Dark dyes are more common triggers, especially dyes used in blue or black clothing made from synthetic materials
These dyes are released more easily when exposed to sweat. Reactions to clothing dyes are found most often in areas where clothing rubs against the skin the most, such as the waist, the neckline, and the underarm area. If dye allergies are suspected, I advise wearing white cotton T-shirts underneath dark shirts, or trying to use only light-colored shirts when exercising. The labels on clothing do NOT indicate what colors of dyes are used.
What products should I stop using? What are examples of products that contain less of the substances that commonly trigger ACD?
The products below do not contain some of the common triggers of ACD. They do not contain any synthetic fragrance additives, natural fragrance additives, botanicals, formaldehyde, methylchloroisothiazolinone, or lanolin. Some are available at major retailers, and others must be ordered via phone or website.
Note that every product must contain some additives, and some people are allergic to less common triggers. Therefore, if these recommendations do not help, you may require further testing. It can take up to 8 weeks of allergen avoidance for your skin to recover.
Your physician will recommend or prescribe a medicated ointment to use during this time to help with the inflammation. Stop using any and all over-the-counter medications, including numbing creams, antibiotic creams, Benadryl cream, tea tree oil, or other.
Almay roll-on deodorant (roll-on only)
Crystal Body Deodorant Stick
Crystal Roll-On Body Deodorant
Vanicream Deodorant for Sensitive Skin (Aluminum Free)
All Free and Clear
Dr. Rajani Katta is the author of Glow: The Dermatologist's Guide to a Whole Foods Younger Skin Diet. To receive future updates on preventive dermatology and the role of diet, sign up here.