THE ANSWER
See a doctor first. Burns from light-based hair removal are a medical issue, and skin that is blistered, broken or badly inflamed needs medical care rather than a hair removal appointment. Once it has healed, the remaining hair can be dealt with. Nothing on this page is a substitute for seeing a doctor.
Why
Burns from laser or IPL usually come down to energy going into skin instead of hair. The device is set for a particular skin tone and hair type, and if those settings are wrong for the person in the chair, the skin absorbs more energy than it should.
That happens most often for two reasons. The first is skin tone. Darker skin contains more melanin, so it competes with the hair for the light, and settings that are safe on lighter skin are not safe on darker skin. The second is operator training. Investigative reporting and injury litigation have both documented cases where the person operating a medical laser had no relevant training at all.
The consequences range from temporary redness through blistering to lasting pigment change, either darker patches or lighter ones. Both can persist for a long time after the burn itself has healed.
None of this means laser is inherently dangerous. It means it is a medical procedure with settings that have to match the person, and the risk of getting that wrong is not evenly distributed.
Will a laser burn scar?
It can, though many do not. Whether a burn scars depends on how deep it went, whether it became infected, and how it was cared for while healing. This is a question for a doctor who can look at it, not one that can be answered from a description.
Why did this happen?
Most commonly because the settings did not suit your skin tone, or because the person operating the device was not adequately trained to judge them. Neither is something you did.
What are my options now?
Medical care first, then time. Once skin has fully healed, remaining hair can be assessed. Electrolysis does not rely on pigment and does not depend on your skin tone, which is why it is often the route people take afterwards. See electrolysis after laser hair removal.
Treating hyperpigmentation after laser
Darkened patches after a burn are a skin matter rather than a hair matter, and they belong with a doctor or dermatologist. Hair removal does not treat pigmentation, and any hair removal provider offering to fix discoloration is offering something outside their scope.
What the evidence says
Cases of second and third degree burns from laser hair removal at medical spas have been documented in news investigations and in injury litigation, including at least one widely reported case in which the operator had no training. Risk is higher on darker skin because of how the technology works. This page describes what has been documented publicly and makes no claim about any particular business.
What to do next
Get it seen by a doctor. Take photographs, keep any paperwork from the provider, and note dates. Do not book further light-based treatment on that area while it is healing.
When the skin has settled, the hair itself is still treatable by a method that does not depend on pigment. See hair removal for darker skin tones if skin tone was a factor.