ABSTRACT
CLINICAL SIGNIFICANCE OF ACNE VULGARIS AND ACNE SCARRING Acne vulgaris (acne) is the most common skin disorder encountered by dermatologists in ambulatory practice, accounting for 11.3% of visits to non-Federal office-based on dermatologists practicing in the United States in 2005.(1) In one comprehensive study of individuals living in the United States aged 1 to 74 years, the prevalence of acne was determined to be 68 per 1,000 for both sexes, 70.4 per 1,000 for men, and 65.8 per 1,000 for women.(2) Other reports have suggested that acne affects 34% to 90% of males and 27% to 80% of females at some point during their lifetime, with the peak incidence reported to be between the ages of 14 and 17 years for females and 16 and 19 years for males.(3, 4) Although adolescents represent the population that is predominantly affected by acne, postteenage acne is not uncommon. One study evaluating patients with a mean age of 39.5 years (age range 25-58 years) reported the presence of active acne in 3% of males and 12% of females.(5) With regard to acne type and/or severity, the prevalence of cystic acne was determined in one analysis to be 1.9 per 1,000 for both sexes, 3.3 per 1,000 for males, and 0.6 per 1,000 for females.(2)
Although prevalence rates for acne vary among different epidemiologic reports depending on the methodology used for analysis, the bottom line is that acne is a very common disorder. Available publications likely underestimate the true prevalence rates of acne and its associated sequelae. This is because the epidemiologic data are based predominantly on those patients who attend dermatology clinics for acne treatment, with only up to 16% of individuals with visible facial acne estimated to actually seek therapy from a physician.(4, 6)
Due to the widespread prevalence of acne, both psychosocial and physical sequelae of the disease are commonly encountered problems that affect many patients in an adverse manner.(4, 6) The negative psychosocial implications of acne are well documented and include association with both currently visible acne and sequelae such as scarring.(7, 8) Adverse psychosocial effects of acne that have been reported are social embarrassment, poor self-esteem, emotional debilitation, social isolation, avoidance of interpersonal interaction, diminished academic performance, altered perception of body image, anger, frustration, anxiety, depression, and suicidal ideation.(7-9) Persistent physical sequelae of acne that are distressing to many patients include postinflammatory hyperpigmentation (PIH), postinflammatory erythema (PIE), and various types of scarring. Acne scarring represents the form of permanent sequelae from acne that is overall the most challenging to treat as outcomes may be variable, and the extent of improvement is usually only partial, depending on the type and extent of scarring that is present.(4, 6, 10, 11)
It is not surprising that acne is a common reason for a dermatologic office visit and that the disease produces negative psychosocial impact for many patients, as 97% of acne cases involve the face.(12) Truncal acne affects approximately half of all cases of acne presenting to a dermatology practice, with only 3% of acne cases involving only the trunk.(12) Over 70% of patients with truncal acne desire treatment for the trunk.(12) Therefore, although emphasis is placed on facial acne in terms of clinical and epidemiologic studies, both active acne and sequelae such as scarring that affects the trunk may also cause significant psychological distress for patients. Postacne scarring is significant in that its presence is particularly devastating to some patients and may in certain cases be a risk factor for suicidal ideation.(13)
PREVALENCE OF ACNE SCARRING Epidemiologic data on acne scarring is limited, and the true prevalence is believed to be unknown.(14) One study reported acne scarring in 14% of women and 11% of men among 749 patients aged between 25 and 58 years.(5) Other publications suggest that between 30% and 95% of patients with acne develop some form of associated scarring.(6, 15) Additionally, a variety of clinical presentations of acne scarring may occur, with some patients demonstrating more than one type of scarring.(4, 6, 10, 11) Although atrophic scarring appears to be the most common type associated with acne, good epidemiologic data are not available on the relative prevalence rates of different types of acne scarring.(4, 16, 17)
IMPORTANCE OF EARLY TREATMENT FOR ACNE TO REDUCE THE RISK OF ACNE SCARRING Scarring may occur early regardless of the severity of acne.(6) Although acne scarring is likely to be associated more often with nodulocytic acne and a greater intensity of visible inflammation, acne scarring may occur in cases with only superficial forms of acne, especially when effective treatment for acne is delayed.(6, 17)
Treatment delay is a significant problem in the management of acne and the prevention of physical sequelae such as scarring and dyschromias.(4) With the advent of multiple over-the-counter treatments that have limited efficacy, options promoted on television or on the internet that are poorly substantiated, and nonconventional therapies through sources not supervised by a knowledgeable physician, patients often use therapies for acne that are either ineffective, are not properly correlated with the severity of their disease, and are not optimally monitored. As a result, their acne persists or worsens, allowing for additional development of new acne lesions, thus prolonging their psychological distress and increasing the risk
of scarring. One study showed that overall, approximately 16% of patients with acne seek proper treatment, and among those seeking such help, 74% wait greater than 12 months, 12% wait 6 to 12 months, 6% wait 6 months, and only 7% wait less than 3 months to be seen professionally for therapy of their acne.(18)
EVOLUTION OF ACNE SCARRING Acne scarring occurs subsequent to visible resolution of deep inflammation. However, scarring may develop even when visible inflammation is minimal and at sites previously affected only by superficial inflammatory acne lesions.(6, 17) Proliferation of Propionibacterium acnes plays a pivotal role in the stimulation of innate immune response and the development of inflammation in acne.(19-21) Inflammation in acne is often initiated before rupture of the follicular wall; however, loss of wall integrity further amplifies the intensity of perifollicular inflammation.(19, 22) In addition, with dermal exposure of P acnes, activation of both the classic and alternative complement pathways occur.(19, 22) Incomplete containment of perifollicular inflammation secondary to follicular rupture may lead to formation of multichanneled fistulous tracts, open comedones, and/or ice-pick scars.(19, 22)
The ultimate appearance of acne scars relates to the extent and the depth of the inflammation.(4, 16, 17) When the preceding inflammation extends significantly into the dermis, degradation of the supporting matrix may be extensive, leading to a greater potential for scarring. Fibrosis and varying degrees of change in skin texture ensue after collagen and other dermal matrix components are damaged by the inflammation of acne. Over the next several months, deposition of new matrix and collagen synthesis occurs during the remodeling phase. Epidermal damage does not result in scarring but may produce persistent erythema or dyschromia, the latter most evident as foci of brown hyperpigmentation in individuals with darker skin types.
