• Dermatology Treatments
• Skin Diseases
• Dermatology Clinical Trials

• Dermatology Treatments
• Skin Diseases
• Dermatology Clinical Trials
• Dermatology

Acne occurs with large overactive sebaceous glands as a result of excessive sebum production, abnormal desquamation of follicular epithelium, and proliferation of Propionibacterium acnes, which may block the gland opening and cause inflammation. Photothermolysis of the sebaceous gland targets these contributors of acne. High absorption and contrast are needed to achieve effective sebaceous gland photothermolysis; however, there is no wavelength that selectively targets the sebaceous follicle. Katarzyna Podolec, MD, Jagiellonian University Medical College, Krakow, Poland, presented the results of 2 studies evaluating a novel approach to the photothermolysis of acne lesions via the delivery of gold microparticles into the sebaceous follicle.

Submicron-sized particles (0.150-μm diameter) consisting of inert gold surrounding a silica core were developed for strong plasmon absorption at 800 nm and were suspended in a topical formulation. When massaged into the skin, the particle suspension is selectively delivered into the sebaceous follicle without epidermal, dermal, or systemic exposure. The excess suspension is wiped from the skin, and the follicle is irradiated with a laser. The particles convert the laser light into heat, which deactivates the sebaceous gland via classical photothermolysis. The gold particles limit heat delivery to the follicle.

In study 1, 48 patients were randomized to 1 of 2 arms: immediate treatment or delayed crossover (control). Patients in the former were treated with the particle suspension and 800-nm laser applied 3 times, at 2-week intervals. Patients in the control arm were treated with a salicylic acid wash for 12 weeks, after which they received only the particle-laser treatment.

The particle-laser treatment was associated with a mean pain level of 4 (scale, 0 to 10) and mild erythema that resolved within 30 minutes. At 12 weeks, there was a significant difference in the mean percentage change in inflammatory lesions from baseline in the treated arm (−34%) vs the control arm (−16%). The rapid decrease of inflammatory lesions in the treated arm continued, with a −61% change at 28 weeks.

After crossing over to treatment, patients in the control arm had a rapid decrease in inflammatory lesions that lasted for 6 months.

In study 2, 49 patients were randomized to 3 particle-laser treatments 1 week apart or 3 sham vehicle-laser treatments 1 week apart. At 16 weeks, the treatment arm had a −38% change in inflammatory lesions, compared with a −16% change in the control arm, at which point the placebo arm follow-up ended. The rapid decrease continued in the treatment arm to −61% at 28 weeks. The Investigator's Global Assessment score (percentage with change > −2%) was 32% in the treatment arm vs 0% in the control arm.

These studies demonstrated the effectiveness of acne treatment with selective photothermolysis of sebaceous follicles via gold particles as compared with controls. The particle-treated patients experienced a mean 61% reduction of inflammatory lesions at 6 months from baseline. The particle-laser treatment was well tolerated with minimal side effects. This new acne treatment is a promising addition to the armamentarium available to physicians.

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