Blue Light Therapy of C. Acnes

Efficacy of Blue Light Therapy in Reducing Cutibacterium Acnes Bioburden at the Deltopectoral Interval

This proposal aims to investigate a novel light-based treatment to reduce morbidity in shoulder surgical patients. This has potential to improve outcomes and reduce health care utilization associated with infectious complications of shoulder arthroplasty. Participants will be healthy male volunteers at least 18 years of age. They will be on study for approximately 2 days.

Participants will have two study visits (consent plus treatment and swabs for culture). These visits will be conducted at the main UW Hospital, UW Health at the American Center, or UW Health at 1 S. Park. All visits will be conducted in reserved conference rooms at each location. Once a subject is determined to be eligible and has consented to the study, they will be randomized into one of three treatment groups. Study team has blank envelopes that contain one of the three treatment groups enclosed. After a subject consents to the study, the study team will randomly draw an envelope to assign a treatment arm. Arm 1. One group will receive 5% topical benzoyl peroxide gel plus 2% chlorhexidine gluconate with 70% isopropyl alcohol Arm 2. One group will receive blue light therapy plus 2% chlorhexidine gluconate with 70% isopropyl alcohol Arm 3. One group will receive both of the above treatments All participants will have their contralateral shoulder serve as the control (2% chlorhexidine gluconate with 70% isopropyl alcohol only). All treatment will be provided by the study team. Participants will also be asked to complete a research intake form. If C. acnes does grow for a tissue culture, Investigators plan to bank a colony of the bacterium for potential use in a future study. There will be no added risk to research subjects as no additional cultures will be taken and samples will be completely anonymized. The banked samples will simply be a colony of growth from the culture media for storage for possible future use. Samples will be banked for 5 years from the date of study completion after which time the samples will be destroyed.

FDA cleared blue light product, Omniluxblue (Globalmed Technologies, Glen Elen, CA), which emits a 415 nm blue light irradiance of 40mW/cm2. Following the application of blue light protective eyewear, the blue light therapy device will be centered over the deltopectoral interval according to device standardized use instructions and a 23-minute treatment will be administered to dry skin. As was done in the topical BPO group, following treatment, a skin swab culture of the treatment shoulder will be taken, then both the treatment shoulder and control shoulder will be sterilely prepped with 2% chlorhexidine gluconate solution with 70% isopropyl alcohol and allowed to dry for 3 minutes. Following chlorhexidine preparation, a single set of cultures will be obtained from each shoulder. Participants and research personnel conducting the blue light treatments will be wearing medical grade blue light protective glasses for safety.

A pea-sized amount, ~0.5 grams, will be applied to a 10cm strip over the deltopectoral interval beginning the morning 48 hours prior to schedule research visit to obtain cultures. The benzoyl peroxide will be applied on dry skin after a shower. The gel will be applied once in the morning and once in the evening for two consecutive days as well as the morning of the scheduled research visit. Following treatment, a skin swab culture of the treatment shoulder will be taken, both the treatment shoulder and control shoulder will be sterilely prepped with 2% chlorhexidine gluconate solution with 70% isopropyl alcohol and allowed to dry for 3 minutes. Following chlorhexidine preparation, a single set of cultures will be obtained from each shoulder.

Prior to treatment, a skin swab culture will be taken, 5% topical benzoyl peroxide treatment will be performed on dry skin immediately after a shower as described in the above paragraph. Again, five total treatments will be performed prior to research visit. On the day of the research visit, the blue light therapy protocol described above will be performed exactly the same followed by culture obtainment.

Swab will be taken from skin and cultured for approximately 7 days to determine bacteria growth. This result is for the null condition following treatment with either blue light, blue light plus benzoyl peroxide or just benzoyl peroxide but before additional preparation with chlorhexidine.

Quantitative culture analysis between treatment groups after treatment to the shoulder but before chlorhexidine preparation (null condition).

Comparison of positive Cutibacterium acnes cultures as a binary (yes/no) outcome between treatment arm and control arm following chlorhexidine (CHX) prep. Reported is the percentage of people in each group that had Cutibacterium acnes growth.

Samples taken from treatment arm and control arm after chlorhexidine (CHX) preparation on both sides.

Males have a higher incidence of C. Acnes. Inclusion criteria includes males 18 years of age and older, as this is the gender and age group most likely to have C. Acnes.

Inclusion Criteria: Healthy male 18 years or older Exclusion Criteria: Allergy to benzoyl peroxide or chlorhexidine <18 years of age Previous history of shoulder infections Antibiotics taken within one month of research visit Immunocompromised state Active cancer Diabetic Skin lesions or abrasions over the deltopectoral interval Topical corticosteroid treatment to either shoulder or or systemic corticosteroid treatment within 2 weeks of research visit Topical benzoyl peroxide treatment to either shoulder within 2 weeks of research visit Blue light therapy treatment to either shoulder within 2 weeks of research visit Prior incision over the deltopectoral interval of either shoulder Contraindication to blue light treatment

Cotter EJ, Cotter LM, Franczek EB, Godfrey JJ, Hetzel SJ, Safdar N, Dai T, Arkin L, Grogan BF. Efficacy of combinational therapy using blue light and benzoyl peroxide in reducing Cutibacterium acnes bioburden at the deltopectoral interval: a randomized controlled trial. J Shoulder Elbow Surg. 2021 Dec;30(12):2671-2681. doi: 10.1016/j.jse.2021.08.008. Epub 2021 Aug 31.