Why does having a tattoo make you more likely to have an allergic reaction to hair dye?
When you have a tattoo, the inks (dyes) they use are injected deep into the skin. The ink stays there because it is trapped onto by cells called macrophages which are part of the body’s immune defense system against infections. If you have a tattoo, your immune system has become familiar with the foreign body ‘ink/dye’ so when you dye your hair there’s a small chance that the body will recognise the dye as ‘foreign’ and attack it, causing an allergic reaction. It’s the same principal as if you’ve had a bad reaction to hair dye before- the body knows what it’s up against and is ready to attack against it. Hope this makes sense.
