From Medscape by Terrence Keaney, MD, FAAD: “An allergic sensitivity to tattoo pigments is a common adverse reaction. Individuals may manifest sensitivity to a particular pigment in several ways, including contact dermatitis or photoallergic dermatitis. This image shows a bullous (or blistering) eczema allergic reaction to a henna tattoo.
Image courtesy of the NIH.”
Tattoo and pigments under the skin can cause infection and reactions. We have not seen issues with infection associated with SMP at New Hair Institute. It probably helps that we are a medical facility and our physicians oversee and perform SMP. We are careful not to go overboard and are generally conservative in our decision making process. We give patients the option for a steroid injection to minimize any reaction. We perform a patch test before the SMP procedure to determine allergies to metals and any topical allergies to the tattoo pigments we use.
The regulations for business offering tattoo or permanent pigment (such as SMP) varies by state and city. It does require a license and registration with local authorities if you are not a licensed medical doctor.
Here is a link for Los Angeles Public Health