Which phrase lists the three laser-induced skin damage mechanisms?

• A. Photomechanical; Thermal; Photochemical
• B. Photothermal; Thermochemical; Photochemical
• C. Photomechanical; Thermal; Photothermal
• D. Photochemical; Photothermal; Photomechanical

Answer: (A)

When laser energy interacts with skin, it can cause damage through three main pathways: mechanical disruption, heating, and chemical changes. The best phrase lists these three: photomechanical, thermal, and photochemical. Photomechanical effects come from rapid energy delivery that creates mechanical stress, plasma, and cavitation in the tissue. Thermal effects come from energy being absorbed and converted to heat, leading to protein denaturation and coagulation. Photochemical effects arise when photons drive chemical reactions that alter tissue components.

The other options mix in less standard terms or omit one of the three core pathways. Thermochemical blends heat and chemistry together in a single category, which isn’t usually treated as a separate primary mechanism. Duplicating heat-based terms or swapping thermal for photothermal leaves out or mislabels one of the three distinct mechanisms. So the combination that matches the common trio—photomechanical, thermal, and photochemical—is the correct one.