Acne is a chronic skin condition that produces pimples and whiteheads when hair follicles and dead skin cells become clogged up. It affects approximately 40 to 50 million people in the U.S.. Acne is not restricted to adolescents, and affects many adults. It is estimated that the condition led to $3 billion in healthcare costs in the U.S. in 2016.
Various treatment options are available to reduce the emergence of pimples and minimize lesions and scaring. Topical retinoids such as tretinoin have emerged as successful treatment options to reduce the appearance of acne. But the success of any treatment usually depends on the biological reasons that caused your acne in the first place.
There are four main molecular causes of acne:
Hormonal acne is caused by fluctuations in androgen levels. It is particularly frequent in women a few days before menstruation. Androgens promote the production of sebum – an oily substance that keeps the skin and hair moisturized. Too much sebum, however, can pile up in the hair follicles and block pores, leading to acne.
The use of tretinoin for the treatment of skin conditions including acne dates back to the 1960s. It was the first retinoid approved by the U.S. Food and Drug Administration (FDA) in 1971.
Retinoids are compounds related to vitamin A that regulate the growth of cells. They are also involved in other important biological processes including vision, inflammation, embryogenesis, and reproduction. Retinoids work by speeding up skin cell turnover. When a retinoid cream or gel is applied to the skin, new skin cells are produced at a more rapid pace. This leaves less time for pores to become blocked.
Various studies have shown that tretinoin (0.1%) reduced the appearance of cysts by 80% when applied daily for 12 weeks. Tretinoin also decreases acne scarring and improves skin texture over 24 weeks.
Although most studies of tretinoin have been in patients with hormonal acne, several trials have shown that it also reduced inflammatory acne. That’s because tretinoin appears to mediate the effect of small proteins known as cytokines. These cytokines have important immune messaging functions and some of them are proinflammatory. Multiple studies demonstrate that tretinoin inhibits the release of such proinflammatory cytokines.
Even though tretinoin is a good treatment to reduce the appearance of acne, it likely won’t cure your acne. You may still experience occasional break-outs, especially before your period. But there are other medications you can take alongside tretinoin to speed up recovery.
If you suffer from hormonal acne, your doctor may prescribe a hormonal oral contraceptive as treatment. Several birth control pills including YAZ, Ortho Tri-Cyclen and Estrostep have been approved by the FDA as acne treatments.
The combination of active hormones contained in combined birth control pills (estrogen and progesterone) helps to reduce the body’s production of androgen, which then minimizes hormonal acne break-outs.
When using hormonal birth control in combination with tretinoin, patients can significantly limit hormonal acne.
However, hormonal birth control isn’t suitable for everyone. For example, women looking to become pregnant or smokers over the age of 35 should not be taking a combined oral contraceptive. In such cases, your doctor may prescribe a course of antibiotics. These act by targeting the bacteria that cause acne.
Antibiotics known to be effective in treating acne include doxycycline, erythromycin, minocycline and tetracycline. In mild cases of acne, topical antibiotics such as clindamycin are used. Long-term therapy with antibiotics is not advised however, as antibiotic resistance can develop. By promoting the growth of resistant bacteria, treating acne can become more challenging.
In most cases, the duration of antibiotic therapy will be between 6 to 8 weeks. In rare cases, therapy is extended to 18 weeks. Oral antibiotics can be taken alongside tretinoin and birth control if needed.
Reviewed by Dr Roy Kedem, MD
Information last reviewed 12/06/21