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.

(of course this is very rare, i myself have tattoos and dye my hair and have had no trouble)

Never heard of that before. It's 13 years since I got my first tattoo, had a few more since & I colour my hair every 3-4 weeks. Never had an allergic reaction to hair dye.

Because anyone who has a tattoo or indulges in any other form of self mutilation has a thin skull and the chemicals in the dye could leak in and cause discomfort to the weak brain inside.

Which thought that the tattoo was a good idea in the first place.

What might've been a good idea at twenty looks like crap at fifty!

Probably got to do with chemical reactions, I'm no medical specialist but I'm just using common sense.

maybe they are trying to stop people putting tattoos on

as i am not one for disfiguring my body and the hair dye people might be the same

or the tattoo chemicals could react to the chemicals in hair dye

as you will have these chemicals on and in your body

now you have used them

so do not mix chemicals together

thats how poisons and bombs are made

it is dangerous if you do not know what you are puttiong together

I've never heard of this and frankly, can't see why it would make any difference at all.

I've never heard that before.