Efficacy of a Non-Comedogenic Hair Care Regimen for the Reduction of Mild-to-Moderate Truncal and Facial Acne: A Single-Arm 8-Week Study.

INTRODUCTION: Hair care products can be comedogenic, and therefore contribute to acne. Hair care products can leave a residue on the skin, even with rinse off products. This residue may explain why hair care products can cause acne. METHODS: 27 subjects aged 16–45 with mild to moderate facial and truncal acne utilized a non-comedogenic hair care regimen for 8 weeks. Dermatologist assessment of acne severity was performed with the PGA (truncal acne) and IGA (facial acne) scale at baseline and 8 weeks. RESULTS: At 8 weeks 70% of subjects with truncal acne showed improvement in PGA, and 52% of subjects with facial acne showed improvement in IGA by dermatologist grading. Subject self-assessment corresponded with dermatologist grading, with 74% agreeing that their skin looks and feels healthier at 8 weeks. CONCLUSION: This non-comedogenic hair care regimen showed efficacy in improving mild to moderate truncal and facial acne, both by dermatologist grading and subject self-assessment. Hair care products should be considered as a possible contributor to acne. J Drugs Dermatol. 2021;20(6):690-693. doi:10.36849/JDD.5772.

Optimal wavelengths for vein-selective photothermolysis.

BACKGROUND AND OBJECTIVE: Oxyhemoglobin (HbO(2)) has been regarded as the primary target chromophore for selective photothermolysis of vascular malformations. In theory, venous lesions might be better treated with wavelengths preferentially absorbed by deoxyhemoglobin (Hb). STUDY DESIGN/MATERIALS AND METHODS: Wavelength-dependent fluence thresholds for photocoagulation of whole human blood were determined in glass capillary samples with measured oxygen saturation levels. Pulsed dye lasers at 585, 590, 595, 600, 633 nm, a 694 nm ruby laser, a 755 nm alexandrite laser, and a 1,064 nm Nd:Yag laser were used, all with 1.5-3 milliseconds pulse width and similar exposure spot size. RESULTS: Selectivity (a lower fluence threshold) for venous blood was maximal at 694 nm, and significant at 595, 600, 633, and 755 nm. At 633 nm, a wavelength with strong relative absorption by metHb, selectivity for venous blood was much less than expected. The Nd:YAG laser at 1,064 nm showed significant selectivity for arterial blood. CONCLUSION: Preferential photocoagulation of venous blood is possible at wavelengths with a high Hb/HbO(2) absorption coefficient ratio. Laser-induced metHb may also affect wavelength-dependent selective photothermolysis. Venular malformations such as port wine stains could potentially be treated more selectively with ~630-780 nm sources. Nd:YAG laser pulses at 1,064 nm tend to affect arterial more than venous blood.