A: Yes, they do.
Deodorants and antiperspirants have ingredients that can irritate the skin and this can lead to thickening and darkening of the delicate underarms skin.
Skin irritation leads to inflammation of the skin and subsequently post-inflammatory hyperpigmentation sets in. Increase in melanin is triggered when skin heals after inflammation or injury.
Common culprits include, but are not limited to, baking soda, parabens (a class of preservatives), fragrance, propylene glycol, and lanolin.
Shaving the armpits can also contribute to skin darkening. Shaving too often, shaving dry, or shaving with a dull blade can lead to skin hardening and skin darkening because of the irritation and abrasions caused. Sensitive skin can also react to irritants in shaving creams and lotions such as fragrance.
If you notice your deodorant is causing armpit skin darkening, stop it immediately. When the irritant is removed, the skin will usually go back to its normal colour after a while.
Treatments that can speed up the lightening of armpit darkening are topical lightening creams which contain pigment lightening agents, or Q switched Nd YAG laser that can break down the pigment faster.
Dr. Tan
