It can occur due to melanin damage. After a few sun exposure it should regain pigmentation. It is very common occurrence. In reviewing your photo there are areas of hyperpigmentation too. The pigmentation can be treated in various ways if it persists. Often after a few weeks pigmentation resolves. If it persists on can use enlighten or IPL to treat it depending on the skin type.
I am not certain what kind of treatment you had. However prior to laser genesis you should avoid irritants to the skin about 2-4 weeks. Most likely your skin is just irritated.
There are several treatments available. You can use steroid (which come in different strength) and Benadry. I doubt there is infection in which case can use topical antibiotic. You can also take Benadryl by mouth. It is over the counter. If you touch it you can get it infected. In my experience with both Fractura and Amorphous 8 the itching is mild.
Blister is very common after treatment for Tattoo removal. Fortunately with Elighten III I have not had issues with scarring.
There are various possibilities. First it could be unrelated to tattoo if it is at a distance from where the laser was done. Infection can happen anywhere and can be coincidental. If it is near the tattoo area then perhaps laser hit the area. The blister will be gone in a few days. I have experience transient swelling but no blister at a sight away from where I lasered.
