Tattoo washing will blister, may be related to laser stimulation, skin allergies, subcutaneous hematoma and other conditions. 1. Laser stimulation: tattoo cleaning is generally using laser tattoo cleaning, in this process, the laser acts on the melanin part, melanin will absorb energy, instantly burst, the pigment decomposition. This process will have a thermal effect, stimulate the body tissue, resulting in small blisters on the skin. 2. Skin allergy: If the patient is sensitive to the instruments used for tattoo washing, it may lead to skin allergic reactions. Typical symptoms of local skin appeared in a series of small blisters, accompanied by skin redness and itching and other symptoms. 3. Subcutaneous hematoma: when washing tattoos stimulate the skin, resulting in subcutaneous hematoma of the skin, so the skin will appear small blisters or even blood blisters, usually accompanied by pain. If blisters appear after washing tattoos, it is recommended to consult a doctor in time and strictly follow the medical advice for standardized treatment.