Why do fractional lasers leave pinhole scars in skin? Is it the machine or the person treating?

Without photos this would be difficult to comment on. However fractional means that a series of ultrafine pulses "pinhole" areas surrounded by normal skin is treated so this may explain the pattern you see.

Fractional lasers leave "pinhole" laser wounds as opposed to removing all of the skin. Sometimes this can result in persistent grid marks after the treatment. In most cases, these can be improved with either additional light laser resurfacing or Micropen treatments or dermabrasion if severe. I hope that you are able to find someone experienced in improving this condition. I hope this information is helpful for you.Stephen Weber MD, FACSDenver Facial Plastic Surgeon

A safe option to improve this problem is micorneedling .There is no downtime and it can improve the scars. It can repeated a few weeks apart.

Grids and patterns after fractional laser treatments are uncommon, however they can be improved. The patterns are due to the size of the laser beam and also depends on how your skin heals. Erbrium ProFractional laser for example leaves a bigger grid pattern- column diameter than Fraxel 1927. As to how to improve things- my suggestion is that you see a Board Certified Plastic or Dermatologist. Lighter resurfacing procedure can be considered, as can fully ablative laser resurfacing. All the bestDr Davin Lim Laser DermatologistBRISBANE, Australia