Recalcitrant acne is a common, unwavering problem in dermatology practices nationwide. However, both gram positive and gram negative infections of the skin can go undiagnosed in patients with acne resistant to the armamentarium of oral and topical therapeutics. Although I often use isotretinoin in patients with cystic or recalcitrant acne, I almost always do a culture prior to initiating therapy, and more often than not, have discovered patients have gram negative and gram positive skin infections resistant to antibiotics commonly used to treat acne.
In a by Bashir and Lambert published in the Journal of Applied Microbiology, 70%-90% of makeup products tested – including lipstick, lip gloss, beauty blenders, eyeliners, and mascara – were found to be contaminated with bacteria. Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli were the most common culprits, and the product with the highest contamination rates were beauty blenders (the small sponges used to apply makeup), which also had high rates of fungal contamination.
Expiration dates on cosmetic products are used to indicate the length of time a preservative in a product can control bacterial contamination. They are printed on packaging as an open jar symbol with the 3M, 6M, 9M, and 12M label for the number of months the product can be opened and used. Unfortunately and unknowingly, most consumers use products beyond the expiration date, and the most common offender is mascara.
Gram positive and gram negative skin infections should be ruled out in all cases of recalcitrant acne. A reminder to note on all culture requisitions to grow gram negatives because not all labs will grow gram negatives on a skin swab. Counseling should also be given to those patients who wear makeup, which should include techniques to clean and sanitize makeup applicators including brushes, tools, and towels. Blenders are known to be used “wet” and are not dried when washed.
It is my recommendation that blenders be a one-time-use-only tool and disposed of after EVERY application. Instructions provided in my clinic are to wash all devices and brushes once a week with hot soapy water, and blow dry with a hair dryer immediately afterward. Lipsticks, mascara wands, and lip glosses should be sanitized with alcohol once a month. Finally, all products need to be disposed of after their expiry.
Dr. Talakoub and Dr. Wesley are cocontributors to this column. Dr. Talakoub is in private practice in McLean, Va. Dr. Wesley practices dermatology in Beverly Hills, Calif. This month’s column is by Dr. Talakoub. Write to them at
Basher A, Lambert P. J Appl Microbiol. 2019..