Your Guide to Underarm Rashes

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Sometimes I’ll receive e-mails from people telling me that they have a baking soda allergy, and can’t use it in a deodorant. I wanted to talk today about this as well as other causes for underarm rashes.  

An allergy is an immune response to a substance that the body sees as “foreign.” It sends white blood cells to attack the foreign substance, usually a protein or a substance that binds to a protein (called a hapten.) Baking soda is a simple substance that’s easily soluble in water and breaks down in to sodium and bicarbonate ions (or to elemental carbon, hydrogen, and oxygen), which are common metabolites in the body. All are elements that the body needs to function. It doesn’t act like a protein or bind to proteins to create a molecule that triggers an immune response.  There’s no function whereby baking soda could be an allergen.

Now, that said, a person can get a skin reaction from baking soda, known as contact dermatitis.  There are two types of contact dermatitis: allergic and irritant.  Baking soda reactions fall under the category of irritant contact dermatitis.  Baking soda is alkaline, so if high amounts are left on skin for a long time it can irritate skin because it disrupts the skin’s acid mantle, leading to moisture loss.  Brief exposures can cause reactions in someone that has severely impaired skin function, such as someone who has been through radiation treatment for cancer, or been through other serious illnesses. But for most of the population, brief or low concentrations of alkalinity are just fine (and can be beneficial for cleansing purposes). Irritant contact dermatitis looks and feels like a burn. One will experience redness, dryness, or scaly/leathery-feeling skin. You will read a lot about this in forums with people making home-made deodorants because baking soda is usually used in too high concentrations in these formulas (usually around 30%, sometimes 100%!).

However, baking soda is usually not the problem
This rarely happens with our deodorants because the baking soda is used at a less than 5% concentration, plus our formula has the moisturizing oils that counteract the possible drying effect of the baking soda.  Additionally, if you sweat at all, you’ll neutralize the baking soda (because sweat is mildly acidic) and it won’t be an irritant any longer.

Most of the time, when using a natural deodorant, rashes are caused by perspiration.  

Intertrigo
Intertrigo is the most common form of underarm rash, which is irritation caused by skin-to-skin friction. When moist skin rubs against itself, that friction causes skin to become inflamed. You’ll start to notice a red, raw spot right in the crease of your underarm (or other folds of skin.) It can progress from there and get larger. If it progresses untreated, it can get flaky, or infected and oozy.

To prevent intertrigo, the key is to reduce the friction in the underarm.  This is best done with a natural powder such as arrowroot or corn starch. Reapplying our Pit Putty sticks frequently throughout the day to keep the underarm dry and friction-free can control intertrigo.  This may seem counterintuitive because when you first get an underarm rash you might blame the deodorant. When in fact the deodorant can definitely help. Of course, if your rash is infected or doesn’t go away, please visit a doctor.

Heat Rash
“This deodorant is clogging my pores!” might be your first reaction to seeing a heat rash because it looks like a bunch of pimples.  Heat rash is actually caused when perspiration gets trapped in your skin, causing infected and blocked pores. Liberally applying powders as mentioned above, frequently throughout the day, will help draw out that moisture and dry up the heat rash.  Cleaning with alcohol (rubbing or ethanol) can also help to dry out the infected pores and help keep the infection from growing. Cortisone creams can also help if you’ve got a tough case. Heat rash can happen in the underarm, the groin area, and other folds of skin that may be moist. If your heat rash doesn’t go away or continues to spread, do see a doctor.

Infected Sweat Gland(s)
Excess perspiration can also cause sweat glands to become infected.  These will feel like deep tender bumps, and your lymph nodes may also become infected. This can also happen during anti-perspirant use, because the blockage that these chemicals cause.  Infected sweat glands can be serious and may require the use of antibiotics to treat. Keeping your underarms dry by applying powders frequently throughout the day can help to prevent infected sweat glands.

Allergic Dermatitis
Allergic dermatitis can be the cause of underarm rashes, although it is less common than the conditions described above. Rashes will present on all areas of skin the product was applied to, but also may spread out from there due to the immune response. Allergic dermatitis can come in the form of a simple rash, but can also be hives, itching, pustules, blisters, and thickening of skin.  If you suspect that you’re allergic to a deodorant, one thing you can do is to apply the product to your wrist and see if you get a reaction on your wrist as well.  Also keep in mind that it can take 1-2 days for an allergic rash to appear, so if you just started a new deodorant and immediately noticed an allergic rash, you may want to consider that it may have been something that you put on your skin within the last 48 hours that’s causing the rash. Additionally, there is a phenomenon called a memory response. If you previously had an allergic reaction, say, on your eyelids from a makeup, if your fingers (but not your eyelids) touch that substance again, your eyelids can flare up, even without that area of skin touching the substance. So if you’re prone to allergic rashes, also consider not just what you put on that area of skin, but what other parts of your body has touched. Allergies can be very tricky to figure out; visit your allergist to pinpoint your exact triggers. 

[For educational purposes only, this information is not intended to treat or diagnose any medical conditions you may have. If you have an underarm rash that persists, visit your doctor. Bubble & Bee Organic does not make any implied or implicit medical or drug claims of our products.]