Update in retinoid therapy of acne.

The pathogenesis of acne, the most common skin disease, is complex and multifactorial. Clinical experience has demonstrated that parallel targeting of various pathogenetic factors, achieved either by mono- or combination therapy with appropriate drugs, represents the most effective approach to treating acne. Topical retinoids have been shown to expulse mature comedones, reduce microcomedone formation, and exert immunomodulatory effects. They have broad anti-acne activity without the risk of inducing bacterial resistance, which justifies their use as first-line treatment in most types of noninflammatory and inflammatory acne and makes them uniquely suitable as long-term medication to maintain remission after cessation of initial combination therapy. Systemic isotretinoin as a monotherapeutic agent strongly affects all four major pathogenetic factors and has been, in the hand of experienced dermatologists, a potent and safe agent for the treatment of severe and recalcitrant acne forms for more that 20 years. However, patient counseling, careful monitoring, and evaluation and management of adverse events are necessary. The use of isotretinoin has experienced a drawback now that its indication has been lowered from a first-line to a second-line medication.