The clinical application of intense pulsed light in the treatment of vascular and pigmented skin diseases has been summarized in the previous two articles (For details, please refer to the clinical application of intense pulsed light therapy device (I), Clinical Application of Intense Pulsed Light Therapy Device (II) Click on the blue font to read the original text). This article will discuss the role of intense pulsed light in the treatment of inflammatory acne and the clinical application plan.

Acne (acne)is a chronic inflammatory skin disease of the hair follicle sebaceous gland unit. People of all ages can suffer from it, with the highest incidence in adolescents. Various types of skin lesions include comedones, inflammatory papules, pustules, nodules, cysts and scars at the opening of hair follicles. According to the nature of the skin lesions, acne can be divided into the following 4 levels:

Level I (mild) - only comedones;

Level II (mild to moderate) - in addition to comedones, there are also inflammatory papules;

Level III (moderate) - in addition to comedones and inflammatory papules, there are also pustules;

Level IV (severe) - in addition to comedones, inflammatory papules and pustules, there are also nodules, cysts or scars.

【Different classifications of acne lesions.

(a) Normal state of normal sebaceous gland units.

(b) Whitehead comedones: closed or whitehead comedones.

(c) Blackhead comedones: open or blackhead comedones.

(d) Papules.

(e) Pustules.

(f) Cysts.

(g) Histological image of sebaceous gland unit.

(h) Histological image of comedones.

(i) Histological image of inflammatory lesions】

I. Acne-specific filters

Sook In Ryu et al. [1] evaluated the efficacy and safety of IPL using dual-band filters (400–600nm and 800–1200nm) for the treatment of facial acne vulgaris.

The study selected 23 subjects with acne vulgaris and treated them with intense pulsed light using a dual-band filter for acne, with parameters set to energy density of 11 to 13J/cm², pulse width of 4.0-5.0ms, and sub-pulse interval of 25-40ms. Both sides of the subjects' faces were treated at 2-week intervals for a total of 5 times. The last follow-up for clinical evaluation was 2 weeks after the fifth treatment, and the indicators evaluated included the number of papules, pustules and comedones, sebum production level, melanin index (MI) and erythema index (EI).

At the last follow-up, the average number of papules, pustules and comedones and melanin index decreased significantly, and sebum production and erythema index did not show statistically significant differences.

【Clinical photo of a male patient showing improvement in acne lesions after treatment. aBefore treatment. bAfter five treatments】

J. Matthew Knight[2] also used a dual-band filter for acne to treat 10 subjects with acne, with a fluence range of 11-17J/cm², a pulse duration of 4.0-5.0ms, and an inter-pulse delay of 25-35ms. A total of five full-face IPL treatments were performed, with an interval of 1-2 weeks, and follow-up was performed at the first and fourth weeks after the last treatment. The evaluation indicators of the treatment effect include: the count of all types of acne lesions on the entire face, the acne 4-level IGA scale, and the Cardiff Acne Disability Index (CADI) scale.

From the results, it can be seen that significant effects were observed 1 week and 4 weeks after treatment, with 62.5% and 80% of the patients showing an improvement of more than 50% in acne lesion counts, respectively; the average IGA score was significantly improved; and the average CADI score was significantly improved. No obvious adverse reactions occurred, so the acne-specific filter showed significant effectiveness and safety in the treatment of facial acne.

【Lesion count and treatment success rate】

[IGA score after treatment]

[CADI score after treatment]

[Comparison between baseline and after treatment]

II. 560nm and 590nm filters

Jin Shunqiao et al. [3] studied the efficacy of intense pulsed light on acne. The study included 61 subjects. Group A was treated with IPL combined with fruit acid; Group B was treated with fruit acid alone; Group C was treated with IPL alone. The final efficacy was evaluated at the 4th and 8th week after the treatment. The parameters of the intense pulsed light were set to 560nm and 590nm filters, energy density 12-16J/cm², the first energy was generally 13J/cm², and the pulse width was 3.0-5.0ms. The appearance of reddish changes in the skin was taken as the treatment endpoint. For individual areas with more obvious inflammation, additional treatment could be given once, and treatment was given once every 4 weeks, for a total of 4 treatments.

From the treatment results, the efficacy of group A was better than that of groups B and C. Group A was more effective in treating inflammatory papules and pustules. No adverse reactions such as pigmentation, hypopigmentation, and scarring occurred in any of the treatment groups.

[Skin lesions of acne patients before and after IPL treatment]

【Skin lesions of acne patients before and after IPL combined with fruit acid treatment】

III. Multiple filter combinations

Tu Handeng et al. [4] used a combination of multiple filters to treat 106 patients with mild to moderate acne vulgaris. They were randomly divided into a control group and an observation group, with 53 cases in each group. The control group was treated with IPL alone, while the observation group was treated with IPL combined with fruit acid. The parameters of IPL were acne/vascular filter combined with 560nm or 590nm, 2 or 3 sub-pulses, pulse width 3-4ms, sub-pulse interval 30-40ms, energy density 15-19J/cm²; acne filter 2 sub-pulses, pulse width 4ms, sub-pulse interval 40ms, energy density 14-16J/cm²; vascular filter 2 sub-pulses, pulse width 4-6ms, sub-pulse interval 30-40ms, energy 16-19J/cm². Treatment was performed once every 3-4 weeks, for a total of 4 treatments.

The results were evaluated using the skin lesion reduction rate and the acne comprehensive grading system GAGS before and after treatment. The effective rate of the control group treated with IPL alone was 73.58%, and the total effective rate after combined treatment with fruit acid was as high as 96.23%; the GAGS scores of the two groups were also significantly reduced.

【Facial skin lesions before and after four treatments of pure intense pulsed light, 2a-c before treatment, 2d-f after treatment】

【Facial skin lesions before and after four treatments of intense pulsed light combined with fruit acid, 1a-c before treatment, 1d-f after treatment】

Fourth, Summary

The mechanism of the intense pulsed light therapy device in treating acne is to use Propionibacterium acnes to absorb pulsed light and stimulate porphyrin to convert into singlet oxygen, destroying cytotoxic substances in the sebaceous glands, thereby inhibiting the formation of acne; at the same time, the thermal effect of the intense pulsed light can also cause inflammatory blood vessels to shrink due to heat, vascular occlusion, and inflammation to subside. During treatment, a special dual-band filter for acne is usually selected according to the patient's skin type and lesion type. 560nm and 590nm filters can be used as an auxiliary, as well as appropriate pulse width, number of sub-pulses, energy density and other parameters, which have significant therapeutic effects.

References:

[1] In Ryu S, Suh D H, Lee S J, et al. Efficacy and safety of intense pulsed light using a dual-band filter for the treatment of facial acne vulgaris[J]. Lasers in Medical Science, 2022: 1-6.

[2] Knight J M. Combined 400-600nm and 800-1200nm intense pulsed phototherapy of facial acne vulgaris[J]. Journal of Drugs in Dermatology: JDD, 2019, 18(11): 1116-1122.

[3] Jin Shunqiao, Zhu Xicong, Zheng Weiqing, et al. Clinical observation of intense pulsed light combined with fruit acid in the treatment of moderate to severe acne[J]. Chinese Journal of Dermatology and Venereology, 2018, 32(07):822-826.

[4] Tu Handeng, Wang Xitao, Hu Yang, et al. Clinical observation of new optimized pulsed light combined with fruit acid in the treatment of mild to moderate acne vulgaris[J]. Chinese Medical Cosmetology, 2022, 12(04):30-34.

Foremed Legend

The core founding team of Suzhou Foremed Legend Medical Technology Co., Ltd. comes from well-known universities at home and abroad such as Peking University. Foremed Legend focuses on the design, development and application of high-end medical aesthetic optoelectronic equipment based on compliance and product strength, and is committed to becoming a leading enterprise in the field of high-end medical aesthetic optoelectronic equipment, a provider of integrated diagnosis and treatment intelligent solutions, and a pioneer of medical aesthetic data integration platform.

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