What can result in worsening of existing keloids?

That really depends on what sort of lasers/skin treatments you are doing. Ablative lasers, deep chemical peels or skin devices like fractional RF breach the skin layer and pose a risk for keloid formation. This is why I personally have both ablative and non-ablative fractional lasers for scar/rejuvenation/wrinkle treatments. If you are only using non-ablative lasers or laser toning, there is negligible risk. In fact, some non-ablative lasers like the pulsed-dye or long pulsed ND:Yag lasers can be useful for treating keloids!

Hi,Yes, TCA cross uses high concentration of Trichloro-Acetic acid (TCA) to injure the skin to cause subsequent skin inflammation, healing and scar improvement. If incorrectly applied or applied in excessive amount, the TCA may indeed cause excessive skin damage resulting in additional scarring including keloid scars. As with most aesthetic procedures, your doctor’s competence and experience will reduce potential side effects to the minimum. Hope this helps!