Does sun exposure prior to a laser treatment increase the risk of burns?

YES!!  
Always discuss your sun exposure with your provider before any laser treatment.
Best of luck,
Michael Kerin MD

It depends on the laser being used. Facial spider veins are usually treated by a laser or IPL/BBL that targets color. If you get sun on your face before a laser, three things happen. You develop a bit of brown pigment called melanin - even if you don't see an obvious burn or tan. 1) The laser or IPL will have to pass through and be absorbed by this to get to abnormal vessels which come up from below and the energy won't get to the vessels so you get less improvement. This is true for treating age spots, too.2) When the laser or IPL is absorbed by this fresh pigment you may burn.3) When you have had recent sun, your melanocytes are activated and in this state, when they are hit by a laser or IPL, you may burn or make abnormal brown pigment - possibly spots, but potentially PIH.Please listen to and discuss any concerns or thoughts with your treating office - they want you to get a great treatment, and get it safely!

Hello!  It depends on what type of treatment your physician is planning for your spider veins.  If an IPL or BBL is part of their treatment plan, definitely avoid sun before the procedure.  These are lights specifically designed to treat color, so a tan or sunburn would increase the energy absorbed.  If he or she is planning just a vascular laser, you would need to avoid sun exposure after the treatment but not before.

Hope this helps!
Dr. Ann

Thank you for your question. You are asking if sun exposure prior to laser treatment for spider veins increases the chances of burns.
I can certainly help guide you with your question, without the benefit of a photo or a physical exam. I’m Dr. Amiya Prasad. I’m a Board Certified Cosmetic Surgeon and Fellowship Trained Oculoplastic Surgeon. I’ve been in practice in Manhattan and Long Island for over 20 years. I use a variety of lasers in my practice, from fractional CO2, fractional erbium, Nd:YAG, Q-Switch, as well as radiofrequency devices for people with darker skin.
Treatment of spider veins is usually just below the skin, so we use the Nd:YAG laser that uses a wavelength that can pass through the surface layer of skin, and ablate the darker veins underneath. If you have darker skin naturally, or have tanned skin from excessive sun exposure, then the treatment may not be as effective. If you normally have lighter skin , we may just wait to treat the spider veins when your tanned skin has faded.
An experienced doctor will know when to treat spider veins, and when to wait if sun exposure has made the skin darker so treatment should be delayed. So, the most important thing is to find an experienced who can present options for treatment, and avoid side effects like laser overexposure and burns. I hope you found this information helpful. Thank you for your question.