Tattoos can look cool, but to psoriatic skin the tattooing process can be a nightmare. Repeatedly piercing the skin and injecting it with dyes is a major trauma. Trauma to the skin can cause new lesions to appear, often 10 to 14 days later. Tattoos can also lead to infection — another psoriasis trigger. Treat your skin with care. Avoid tattoos and acupuncture, and talk with your doctor about shots.