Inflammation in Rosacea and Acne: Implications for Patient Care

Rosacea and acne are chronic inflammatory skin conditions that share an inflammatory pathogenesis, but clinically remain quite distinct. Although many have long assumed that these conditions are primarily infectious, emerging evidence suggests that inflammation plays a critical role in the pathogenesis of these disorders. Part of the innate immune system, the antimicrobial and proinflammatory cathelicidins, may be downregulated by both azelaic acid and subantimicrobial doxycycline. In acne, the creation of papules, pustules and nodules is clearly mediated through immune mechanisms, and the antiinflammatory effects of retinoids play a key role in management. Recent observations help us understand in greater detail the role that inflammation plays in these two diseases, and the mechanisms by which commonly used medications exert their effect by modulating inflammatory processes. This review will present and synthesize recently acquired information as it relates to inflammatory acne and rosacea pathogenesis and clinical management.