How to choose the best deodorant for sensitive skin

Studies(1) show that as many as 23% of women and 13.8% of men experience at least one adverse skin reaction per year due to a personal care product. In fact(2), deodorants and antiperspirants are two of the most frequently tested personal-care products, with millions of consumers applying them to their underarms everyday(3), and subsequently experiencing sensitivity and other skin reactions.

Sweat is odorless, only acquiring a smell when it reacts to the bacteria present on the skin. Everyone has bacteria on their skin, but the way it reacts to sweat differs from person to person.
There are two ways to block odor: by masking the smell or by preventing sweat.

Deodorant, a smell-blocker, is used to deodorize or mask the smell caused by this bacteria reaction. On the other hand, antiperspirant, a sweat-blocker, is used to stop sweat. The formulas are designed to plug up the underarm pores, prevent sweat from escaping and reacting with the bacteria. No sweat means no bacterial reaction, which means no odor(3).

Both deodorant and antiperspirant are used on an area of the body that is prone to sensitivity. The thin, delicate skin under the arms can be particularly vulnerable to sensitivity, especially when perspiration and bacteria are involved. In fact, the underarm area also experiences greater transepidermal water loss (TEWL) and lower amounts of Natural Moisturizing Factors (NMF). This means that the skin is less able to retain water and is more likely to be dry.
On top of this, repetitive behaviors like shaving and waxing also weaken the skin barrier and can result in dry, flaky skin(4). In addition, shaving the underarm consistently removes skin and the hair that is protecting it. These factors, along with heat, humidity, friction with clothing and deodorant can result in a skin reaction or a susceptibility towards skin sensitivity(3).

It’s important to choose deodorants that are hypoallergenic and developed for and tested on sensitive skin. Ingredients like Vichy Mineralizing Water, D-Panthenol, coconut oil and minerals like sodium, calcium, carbonate and magnesium present in our deodorants also have soothing properties for sensitive skin. It’s also a good idea to avoid certain essential oils(5) that can aggravate sensitivity, such as ylang-ylang and lemongrass oil. “It’s important to be conscious about organic skincare products in general, especially the ones with essential oils can also irritate the skin”, advises dermatologist Dr. Nina Roos.

Additionally, new technologies, such as MgO (Magnesium oxide) in deodorant, are worth keeping an eye on. This ingredient is the same used by gymnasts to absorb moisture from their hands and has been proven to be effective as an antibacterial agent. It is able to neutralize the acidic molecules responsible for body odor, and is as efficient at preventing odor as an antiperspirant. Studies* have shown that it reduces 30% of odor 48 hours after the last application. Moreover, as magnesium oxide can absorb twice its weight in water (4 times more than talc), it is also efficient in keeping your underarms fresh and dry, for all day long relief.


*Confirmed in vivo by sensorial testing

Signs of sensitivity, which don't necessarily flare up immediately after application of deodorant, often include:
●       Rashes
●       Burning sensations
●       Itchiness
●       Dry patches.

SOURCES:
1. Orton, DI. et al, 'Cosmetic allergy: incidence, diagnosis, and management' in Am J Clin Dermatol. (2004) 5(5) pp.327-37.
2. Uter, W. et al, 'Patch test results with patients' own perfumes, deodorants and shaving lotions: results of the IVDK 1998-2002' in J Eur Acad Dermatol Venereol. (2007) Mar; 21(3):374-9.
3. Zirwas, M. et al, 'Antiperspirant and Deodorant Allergy' in The Journal of Clinical and Aesthetic Dermatology (2008) Sep; 1(3): 38–43.
4. Turner, G.A, 'Impact of shaving and antiperspirant use on the axillary vault' in International Journal of Cosmetic Sciences 29.1 (2007) pp.31-8
5. Lalko, J. et al, 'Investigation of the dermal sensitization potential of various essential oils in the local lymph node assay' in Food Chem Toxicol. (2006)