The punk-rock NCIS actress Pauley Perrette had an allergic reaction to her hair dye recently, and it caused her eyes to swell up. Perrette, who plays gothic forensic scientist Abby Sciuto on the hit TV show, said she had dyed her hair black, like she’s been doing for years to keep up with the iconic character that she plays in the show.

Perrette posted this photo of herself on her personal Twitter Saturday:

 

 

 

And followed up with this photo statement.

 

 

Wasn’t sure if I should tweet about this, but it’s important. Did my head look a big puffy on the red carpet last night? Turns out I was having a dangerous allergic reaction to hair dye.  Been battling this for a year now, but it gets worse every time. It’s an acquired allergy for people that dye their hair for years (Y’all know I’m blonde) Was in ER. Just got home from hospital. Awful. My head swelled up huge like a melon. If you or someone you know dyes their hair, especially black, please google “hair dye allergy”. Know the symptoms. It can be fatal. People have died. For real.

Perrette’s right; allergic reactions can happen at any time. According to Baylor College of Medicine News, no matter how long you’ve been using the same product, an allergy can develop. "One allergic reaction we're seeing commonly is to hair dyes,” said Dr. Rajani Katta, professor of dermatology at BCM. “It may start as a mild reaction, but it can get worse over time and spread to other parts of the body."

Symptoms can include redness of skin and itching on the hairline, face, eyelids, ears, neck, and back. The chemical p-phenylenediamine (PPDA) is responsible for this allergic reaction. Katta says that people should try to avoid this chemical if they can, and look for "ammonia-free" or "all-natural” products. PPDA can even be found on non-permanent products, so make sure to check.