Frequently used topical retinoids include adapalene, isotretinoin, retinol, tazarotene, and tretinoin.[47] They often cause an initial flare-up of acne and facial flushing, and can cause significant skin irritation. Generally speaking, retinoids increase the skin's sensitivity to sunlight and are therefore recommended for use at night.[1] Tretinoin is the least expensive of the topical retinoids and is the most irritating to the skin, whereas adapalene is the least irritating to the skin but costs significantly more.[1][83] Most formulations of tretinoin cannot be applied at the same time as benzoyl peroxide.[15] Tazarotene is the most effective and expensive topical retinoid, but is not as well-tolerated.[1][83] Retinol is a form of vitamin A that has similar but milder effects, and is used in many over-the-counter moisturizers and other topical products.
What's Going On: Do you tend to get these at the same time every month — say, just before you get your period? Because these are the work of fluctuating hormones, says Joshua Zeichner, a dermatologist and the director of cosmetic and clinical research in dermatology at Mount Sinai Hospital in New York City. Hormones can put oil production into overdrive, and having an excess of it means that it’s more likely to settle in your pores and cause zits.
There are several low-level light devices designed as at-home acne remedies on the market—but do they really work? Some, like the Zeno electronic "zit-zapper" are FDA-approved as acne remedies, but reviews with these products are typically mixed. Even the best acne treatment won't work for everyone, as the severity of the acne, types of acne and quality of the device are all factors. Ask your dermatologist for a recommendation if you're considering purchasing an at-home light device to treat your acne.

Antibiotics are frequently applied to the skin or taken orally to treat acne and are thought to work due to their antimicrobial activity against C. acnes and their ability to reduce inflammation.[20][80][86] With the widespread use of antibiotics for acne and an increased frequency of antibiotic-resistant C. acnes worldwide, antibiotics are becoming less effective,[80] especially macrolide antibiotics such as topical erythromycin.[16][86] Therefore, they are not recommended for use alone but are preferred as part of combination therapy.[15] Commonly used antibiotics, either applied to the skin or taken orally, include clindamycin, erythromycin, metronidazole, sulfacetamide, and tetracyclines such as doxycycline and minocycline.[47] Doxycycline 40 milligrams daily (low-dose) appears to have similar efficacy to doxycycline 100 milligrams daily and has fewer gastrointestinal side effects.[15] When antibiotics are applied to the skin, they are typically used for mild to moderately severe acne.[20] Antibiotics taken orally are generally considered to be more effective than topical antibiotics, and produce faster resolution of inflammatory acne lesions than topical applications.[1] Topical and oral antibiotics are not recommended for use together.[86]

If you notice that you’re breaking out right around your period every month, your acne might be linked to hormones. “A sensitivity to the hormones called androgens manifests in the form of cystic acne,” says Linkner. Androgens, namely testosterone, cause the skin to produce more sebum. More sebum equals more acne. Birth control, which has estrogen and progestin, helps keep hormones balanced and skin clear. Ortho Tri-Cyclen, Estrostep, and YAZ are all FDA-approved as acne treatments.
A major mechanism of acne-related skin inflammation is mediated by C. acnes's ability to bind and activate a class of immune system receptors known as toll-like receptors (TLRs), especially TLR2 and TLR4.[45][64][65] Activation of TLR2 and TLR4 by C. acnes leads to increased secretion of IL-1α, IL-8, and TNF-α.[45] Release of these inflammatory signals attracts various immune cells to the hair follicle including neutrophils, macrophages, and Th1 cells.[45] IL-1α stimulates increased skin cell activity and reproduction, which in turn fuels comedo development.[45] Furthermore, sebaceous gland cells produce more antimicrobial peptides, such as HBD1 and HBD2, in response to binding of TLR2 and TLR4.[45]

Many skin conditions can mimic acne vulgaris, and these are collectively known as acneiform eruptions.[28] Such conditions include angiofibromas, epidermal cysts, flat warts, folliculitis, keratosis pilaris, milia, perioral dermatitis, and rosacea, among others.[20][72] Age is one factor which may help distinguish between these disorders. Skin disorders such as perioral dermatitis and keratosis pilaris can appear similar to acne but tend to occur more frequently in childhood, whereas rosacea tends to occur more frequently in older adults.[20] Facial redness triggered by heat or the consumption of alcohol or spicy food is suggestive of rosacea.[73] The presence of comedones helps health professionals differentiate acne from skin disorders that are similar in appearance.[8] Chloracne, due to exposure to certain chemicals, may look very similar to acne vulgaris.[74]
How to Handle It: Your best bet is benzoyl peroxide. "Benzoyl peroxide can kill acne-causing bacteria and reduce inflammation," says Zeichner. Try a cream like the La Roche-Posay Effaclar Duo Dual-Action Acne Treatment ($37), which also exfoliates with lipo-hydroxy acid. Be aware that it can seriously dry out skin so moisturize well after you use it.
Cortisone is a quick fix for acne emergencies. We mean got a big board meeting tomorrow kind of quick. Go into the dermatologist’s office for a shot of this corticosteroid, and acne will disappear in 24 to 48 hours. The treatment works to curb inflammation, which makes it best for cystic breakouts and can be really good at combatting hormonal flare-ups. If done incorrectly, a cortisone shot can leave a small depression in the skin that lasts about eight weeks. “It’s a rare side effect that happens if dosage of cortisone is too high,” explains Linkner. “You want to go to someone who knows what they’re doing.”

Systemic therapy refers to acne medication that is taken by mouth. Antibiotics like tetracycline, minocycline, doxycycline, or erythromycin may treat moderate to severe acne by targeting bacteria and reducing inflammation. Other systemic therapies include oral contraceptives, which can reduce acne in some women, spironolactone, an anti-androgen hormone pill, and isotretinoin (high-dose prescription vitamin A). Isotretinoin is used only in certain severe, cystic acne cases, or in cases where other treatments don't work. A course of isotretinoin treatment requires regular appointments with your dermatologist.
If you notice that you’re breaking out right around your period every month, your acne might be linked to hormones. “A sensitivity to the hormones called androgens manifests in the form of cystic acne,” says Linkner. Androgens, namely testosterone, cause the skin to produce more sebum. More sebum equals more acne. Birth control, which has estrogen and progestin, helps keep hormones balanced and skin clear. Ortho Tri-Cyclen, Estrostep, and YAZ are all FDA-approved as acne treatments.
This inflammatory cascade typically leads to the formation of inflammatory acne lesions, including papules, infected pustules, or nodules.[1] If the inflammatory reaction is severe, the follicle can break into the deeper layers of the dermis and subcutaneous tissue and cause the formation of deep nodules.[1][66][67] Involvement of AP-1 in the aforementioned inflammatory cascade leads to activation of matrix metalloproteinases, which contribute to local tissue destruction and scar formation.[45]
There are two big guns used to take down acne, and they're both great at doing entirely different things. Salicylic acid is a beta hydroxy acid that comes from willow bark and works primarily as an exfoliator, breaking down fatty acids like sebum so your pores don’t clog. (Glycolic acid works similarly but is less effective.) These acids are effective on comedones — whiteheads, blackheads, and other non-red bumps.
From the What to Expect editorial team and Heidi Murkoff, author of What to Expect the First Year. Health information on this site is based on peer-reviewed medical journals and highly respected health organizations and institutions including ACOG (American College of Obstetricians and Gynecologists), CDC (Centers for Disease Control and Prevention) and AAP (American Academy of Pediatrics), as well as the What to Expect books by Heidi Murkoff.
Flutamide, a pure antagonist of the androgen receptor, is effective in the treatment of acne in women.[100][107] It has generally been found to reduce symptoms of acne by 80 or 90% even at low doses, with several studies showing complete acne clearance.[100][108][109] In one study, flutamide decreased acne scores by 80% within 3 months, whereas spironolactone decreased symptoms by only 40% in the same time period.[109][110][111] In a large long-term study, 97% of women reported satisfaction with the control of their acne with flutamide.[112] Although effective, flutamide has a risk of serious liver toxicity, and cases of death in women taking even low doses of the medication to treat androgen-dependent skin and hair conditions have occurred.[113] As such, the use of flutamide for acne has become increasingly limited,[112][114][115] and it has been argued that continued use of flutamide for such purposes is unethical.[113] Bicalutamide, a pure androgen receptor antagonist with the same mechanism as flutamide and with comparable or superior antiandrogenic efficacy but without its risk of liver toxicity, is a potential alternative to flutamide in the treatment of androgen-dependent skin and hair conditions in women.[105][116][117][118]
Pimples are raised red spots with a white center that develop when blocked hair follicles become inflamed or infected with bacteria. Blockages and inflammation that develop deep inside hair follicles produce cystlike lumps beneath the surface of your skin. Other pores in your skin, which are the openings of the sweat glands, aren't usually involved in acne.