Tattoo removal hyperpigmentation?

Thanks for your question. Firstly, it wouldn’t be accurate to say that fading of tattoos occurs and vanishes completely after 3 weeks from the fifth session. Depending on the color and depth of the tattoo, subsequent sessions may be necessary to perform specific shots. As these shots create a steam on the skin surface, it's appropriate to gently wipe the skin in between shots with a soft cloth several times.
Laser devices such as Pico Sure or Pico Discovery operate by delivering shots using a Pico pulse duration of 1001 nanoseconds, which is a trillionth of a second. This allows for the eradication of tattoos and permanent makeup, including colored tattoos, without causing tissue damage. When the Pico laser pulse hits tattoo or permanent makeup pigment, it generates gas and vapor in the skin. The enhanced photo-acoustic shockwave can reach wider and deeper marks, completing the tattoo removal process in multiple scans during a single session.
Factors influencing the number of sessions include:
Patient's age and skin type,Area of the tattoo,Layering of the tattoo,Coverage area by the colors used and depth of the tattoo,Size of skin damage after application,Care exhibited by the patient post-treatment.One important aspect to consider is the necessity for applying different wavelengths based on colors. Hence, the range of technology and tools used is crucial, depending on the depth and colors of the tattoo present in the patient.
Tattoo Removal Process:
The area with the tattoo intended for removal is cleaned, and a photograph is taken.Local anesthetic numbing cream is applied, followed by a waiting period for its effect before commencing the Pico laser application.The removal process varies depending on the tattoo's size but typically lasts around 20 minutes for a 100 cm² tattoo.Careful post-application maintenance is conducted.Subsequent sessions are scheduled, varying from person to person, usually taking place approximately 4 - 6 weeks apart.Consistent moisturization of the tattooed area and the use of high-factor sunscreen are crucial post-procedure."

This can happen after any laser treatments but can happen after laser tattoo removal of colored ink and needs more sessions to get it to lighten again. Lightening creams and cosmelan can help. I suggest seeing a cosmetic dermatologist. Best, Dr. Emer.