Treatment of Acne: Phototherapy with Blue Light

Voraphol Vejjabhinanta, Anita Singh, and Keyvan Nouri

Department of Dermatology and Cutaneous Surgery, University of Miami,

Miller School of Medicine, Miami, Florida, USA

17.1 I ntroduction

Acne vulgaris is a common skin disease that affects most people at some time or the other during their lives. Its prevalence has been estimated to be about 85-100% in boys aged 16-17 years, and 83-85% in girls of the same age [1,2]. In fact, in the United States, it is estimated that 85-100% of all adolescents will be afflicted with this disease and approxi­mately 25 million adults and 40 million adolescents are affected by this condition [3,4]. Even though it is common in teenagers and early adults, acne can occur in all age groups [5,6]. Twelve percent of women who were at least 25 years old had acne, and this percentage did not diminish until after the age of 44 years [7].

Acne is a multifactorial disorder of pilosebaceous units, and it affects the areas of skin with the greatest density of sebaceous follicles. These areas include the face, neck, chest,

Gurpreet S. Ahluwalia (ed.), Cosmetic Applications of Laser and Light-Based Systems, 341-351,

© 2009 William Andrew Inc.

and the back. In some cases, it can occur at some pressure areas, such as the jawline (due to usage of helmet) or buttock area, or it can occur after using some chemical substances such as cosmetics or hair-styling products. In addition, acne can be caused by a variety of factors, including genetics, hormones, mechanical irritation, and chemical products and organisms.

Acne is characterized by noninflammatory, as well as inflammatory lesions. The nonin­flammatory lesions consist of open and closed comedones. Open comedones (blackheads) are small follicular papules containing a central black keratin plug, formed mainly due to the oxidation of the melanin pigment. Closed comedones (whiteheads) are follicular papules without a visible central plug, due to the keratin plug being trapped deep beneath the epider­mal surface. Closed comedones are potential sources of follicular rupture and inflammation. Inflammatory acne is characterized by erythematous papules, nodules, and pustules [8].

The severity of the acne has been classified by the American Academy of Dermatology according to the following specifications: Mild acne is characterized by the presence of comedones, few papules and pustules (generally <10) but no nodules; Moderate acne has several to many papules and pustules (10-40) along with comedones (10-40); Moderately severe acne is characterized as the presence of <40 papules and pustules along with larger and deeper nodular inflamed lesions (up to 5); Severe acne is characterized by the presence of numerous or extensive papules and pustules, as well as many nodular lesions [9 ] . Although this condition will improve in most patients with time, in some it does not, and these patients have serious long-term effects from acne. These include redness, hyperpig­mentation, and permanent scars (atrophic, hypertrophic, and keloids) [10 ] , which may cause psychological problems such as social phobia, lowered self-image, and even depres­sion in some patients [11].

The cost of acne treatment in the United States is estimated to be more than $1 billion per year, with $100 million spent on over-the-counter anti-acne agents [12]. There are many methods for acne treatment. These acne treatments can be classified into three groups: topi­cal medications, oral medications, and surgical/physical agents [13].

The benefits of topical therapy include its easy application and the lower systemic com­plications or systemic side effects, which is beneficial for some patients or parents con­cerned about taking systemic agents. However, there are some unwanted reactions such as dryness, irritation, allergic contact dermatitis, or less efficacy when compared with sys­temic agents.

Oral medications are prescribed to patients with moderate to severe acne. They are more effective than topical medications; however, there is an increased risk of systemic complications/side effects. For example, tetracycline is an effective antibiotic for acne; however, its side effects include gastrointestinal disturbance, photosensitivity and teeth discoloration [14,15] . In addition, isotretionine, which is very effective in recalcitrant acne [16 , 17], has multiple side effects. These side effects include dry mouth, dry eyes, abnormal serum lipid profile, and its teratogenic effects to the fetus [18,19].

Surgical/physical therapies are another option for acne treatment. These therapies can be used alone, or in combination with topical/oral medications to accelerate the treatment. There are many methods for surgical/physical therapies, including microdermabration, chemical peeling with glycolic acid, salicylic acid, or tricholoacetic acid. Most of these treat­ments claim to treat hypercornification or follicular obstruction. Side effects include burning, a stinging sensation, irritation; and in severe cases, postinflammatory hyperpigmentation or scarring after procedures [20,21]. However, because of advancement in emulsion technol­ogy and drug-delivery systems, many cosmetic companies make these treatments in special
over-the-counter formulas, which reduce concentrations and side effects, but remain still effective.

Nevertheless, there are many patients who have a contraindication to these therapies, or do not show improvement in their acne problems, and are not satisfied with the current treatment. These patients need a new modality which is safe, painless, and different from other on-going methods and is more effective. These are the reasons why phototherapy has evolved (Table 17.1).