Topical antibiotics have been used for decades to treat inflammatory acne. They work by reducing the number of bacteria within the hair follicle and by suppressing the inflammation that causes red, swollen spots.
The most commonly prescribed topical antibiotics are clindamycin and erythromycin. These medications are available as gels or lotions.
Topical antibiotics are most effective for inflammatory acne, where patients develop red papules and pustules. They are much less effective for blackheads and whiteheads because they do not prevent pores from becoming blocked. For this reason, they are frequently combined with other treatments such as topical retinoids, which help keep the pores open.
Dermatologists often prescribe topical antibiotics together with benzoyl peroxide. Benzoyl peroxide rapidly kills acne bacteria through an oxygen-dependent mechanism to which resistance cannot develop.
Several highly effective combination preparations are available: * Duac: Clindamycin with benzoyl peroxide. * Treclin: Clindamycin with tretinoin.
Side effects are usually mild and may include skin dryness, irritation, redness, or a mild burning sensation when treatment is started. Clindamycin and erythromycin are generally very well tolerated, making them suitable for many patients with sensitive skin.
Topical antibiotics may also have a role during pregnancy. In women who cannot use retinoids or oral tetracycline antibiotics, topical clindamycin or erythromycin can often be prescribed safely, frequently in combination with azelaic acid.