Both ohmic thermolysis and 940 nm laser cause damage to the squamous epithelium and papillary reticular dermis that is transient, according to a recent study that compared different heat modalities for the treatment of telangiectasia. It was also found that ohmic thermolysis provides vessel clearance of >90% in telangiectasias <0.5 mm, while 940 nm laser effectiveness is <70% for vessel clearance, but improves to >90% when sclerotherapy is performed at time of treatment. A total of 135 patients were treated over a 2‐year period using ohmic thermolysis (45), 940 nm laser (50), and 940 nm laser with sclerotherapy (40). After treatment, 1 mm biopsies were done in selected patients in each group. Researchers found:

• Ohmic thermolysis produces electrodessication of the squamous epithelium, reticular dermis, and fusion of the target vessel.
• 940 nm laser results include squamous epithelial damage, subcutaneous water blister, collagen denaturation, and vessel endothelial cell loss with thrombus at point of maximal impact.
• The addition of sclerotherapy at time of laser potentiates vessel damage.
• There were no long‐term skin sequelae after treatment when each device is used at recommended settings and on appropriate vessel size.