NCIS forensic scientist Abby Sciuto is known for her jet-black hair, but actress Pauley Perrette shared a photo demonstrating that dying her hair has become hazardous to her health.

In fact, Pauley suffered a severe allergic reaction to hair dye, causing her face to become swollen and puffy. As she wrote on Twitter, she’s acquired an allergy to hair dye that has grown worse, and has suffered from the problem for the past year. The latest allergic reaction actually sent her to the ER.

Pauley cautioned anyone who dyes their hair — especially black — to investigate “hair dye allergy”; on Google. “Know the symptoms,”; she writes. “It can be fatal. People have died. For real.”;