The use of light in the treatment of acne vulgaris—a review

Topical and oral antibiotic therapy is also a popular method of treatment. The effectiveness of this method is limited by the increasing resistance of bacteria to antibiotics. Over the decades since the introduction of antibiotics to treat acne, the resistance levels of bacteria have changed. This defense mechanism is developed evolutionarily. Modifications of antibiotic receptor sites, alteration of drug influx/efflux, or enzymatic degradation are common mechanisms used by bacteria to initiate and strengthen internal antibiotic resistance. The basic chromophores used in light therapy are hemoglobin, melanin, water bound to proteins, and porphyrins. Hemoglobin absorbs light mainly at 580 nm, while melanin absorbs the entire visible spectral range (400-750 nm). Porphyrins are aromatic compounds, classified as photosensitizing substances, intensively absorbing blue light, and to a lesser extent in long visible bands, such as orange and red light. Using IPL makes it possible to cover the maximum light absorption of porphyrins and hemoglobin, therefore it can be an effective tool in the treatment of inflammatory lesions in acne vulgaris. In view of the effectiveness of light therapy and its effect even on antibiotic-resistant bacteria, it is worth considering the possibility of using light therapy instead of antibiotic therapy. Due to the increasing resistance of bacteria to antimicrobials, they should be used with caution and as a last resort. The high-energy light treatment act only locally (unlike with antibiotics taken orally) and on a chromophore, such as melanin, hemoglobin, or porphyrins.