Cosmetic Dermatology
Dermatology Times January 2014
Zoe Diana Draelos, M.D., is a Dermatology times editorial adviser and consulting professor of dermatology, Duke University School of Medicine, Durham, N.C.
Q: Why do antiperspirant/deodorant cause skin irritation?
A: Antiperspirants and not deodorants are the culprit in skin irritation. The antiperspirant decreases sweating while the deodorant simply provides a pleasant scent to the armpit.
The active ingredient in all widely marketed antiperspirants is an aluminum salt possibly mixed with a zirconium salt. The aluminum salt is very irritating to the skin, especially in high concentration. As a matter of fact, the aluminum salt functions to decrease the release of perspiration from the armpit by coagulating protein in the eccrine and apocrine sweat ducts, and it may also coagulate the stratum corneum protein lining the armpit as well. More modern antiperspirant formulations minimize this irritation by incorporating dimethicone, listed on the skin protectant monograph.
For patients that experience irritation from antiperspirant/deodorant and wish continue using these products, it is possible to offer some advice. The antiperspirant/deodorant should be applied at night since the armpit is at rest with less sweat and will work better. In the morning, a thin dimethicone-based moisturizer could be applied to the armpit. This provides a compromise between sweat reduction and skin irritation.
Q: Do lipsticks protect against lip sun damage?
A: Lipsticks provide excellent photo protection if they are completely opaque. As a matter of fact, opaque lipsticks provide better photo protection than SPF- containing lip balms because they have an unlimited SPF and excellent substantivity. Substantivity is the ability of the lipstick to remain in the place on the lip. Products that stay on better provide superior longer-lasting photo protection. The best lip sunscreen for female patients with actinic cheilitis is an opaque lipstick.
Q: Do lipsticks contain lead?
A: The presence of lead in lipsticks has created a stir on consumer websites. Indeed, there are some dyes, especially red dyes, which are used in lipsticks that may contain trace amounts of lead. Remember that the government regulates the pigments used around the mouth, where ingestion may occur. This regulation is necessary to prevent safety issues. The trace amounts of lead that may be found in lipsticks are not felt to be health issue and indeed the amounts are very small compared to the lead contamination possibilities from old lead based paints.
Q: Which sunscreens are more likely to cause acne?
A: Many patients claim that they do not wear sunscreens because they cause acne. I do not believe that it is the organic and inorganic filters that cause acne, but rather the vehicle in which the sunscreens are suspended. It is even unclear that the vehicles contain ingredients that cause acne.
Most patients that complain of acne within 48 hours of applying sunscreen probably are not experiencing true acne with follicular contact dermatitis or possibly miliaria rubra and miliaria pustulosa. The irritant contact dermatitis could be due to the emulsifier in the formulation and the miliaria rubra or miliaria pustulosa could be due to occlusion of the ecrrine sweat units with the sunscreen film.
It is hard to generalize as to which sunscreen formulations are more likely to cause acne-like skin problems, but thicker creamier products are probably the culprits. It may be worthwhile to suggest to patients who claim that sunscreens cause acne-like eruptions to consider a spray formulation.
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