Title: Effect of blue and red led on inflammatory acne: Controlled and randomized clinical trial

Abstract

Inflammatory acne is the leading cause of visits to dermatologists'offices. Topical products such as retinoids are used to treat acne, but they havecutaneous side effects. Acne usually improves after exposure to sunlight or artificially produced sunlight. The purpose of this research is to compare the effect of combined blue/violet, red and blue and red LED lights on grade II and III inflammatory acne. We will recruit 144 participants, aged between 12 and 25 years, with a Fitzpatrick rating scale from I to IV, with mild to moderate inflammatory acne and will be randomized into4 groups: G1: mask with blue LED 415 nm (± 20); G2 : mask with red LED 660 nm (±20); G3: mask with combined red and blue LEDs (415 nm and 660 nm) and G4 -Control - Peeling with 20% salicylic acid once every 15 days. The evaluations will be carried out on the first, fifteenth and thirtieth day of treatment, verifying the reduction of erythema and skin appearance and the degree of oiliness through clinical evaluation. Descriptive analysis will be performed for all variables and data, presented as absolute number, mean and standard deviation (SD). The p-values after the Wilcoxon classification test will also be calculated for statistical significance.