Semi perm hair dye allergy test....Do you?

[CallarMorvern]

I know I should and it's sensible as my head may expand to the size of a football or my hair might fall out and all that. But if you always use the same semi permanent colour, do you actually do the 48hr test or not? It's such a pain, when my hair grows so fast that I have to colour every 3 weeks.

I've never patch tested anything, permanent or semi-permanent

I know I should but I've never had an allergic reaction to a hair dye so I don't bother

They can and do change the formula so you can be fine for years and suddenly have chemical burns. Not worth the risk unless you are checking the ingredients haven't changed from the last time.

That being said I have a mobile hairdresser and she never patch tests me now (been doing my hair for 4 years and does the roots every time then ombre touch up every 9/10 months) and the professional formulas don't really change apparently.

They can and do change the formula so you can be fine for years and suddenly have chemical burns

Well, no this isn't quite correct., You can suddenly have an allergic response, and in fact it is just as possible with a substance that you have been having no reaction to previously, as with a new ingredient.

To get an actual chemical burn you would need to come in contact with a substance that will burn everyone regardless. That should never happen with today's stringent batch tests but it is not impossible. It has nothing to do with allergy though.

it is just as possible with a substance that you have been having no reaction to previously, as with a new ingredient.

See, this is another thing that makes me wonder if testing is worth it, as I could still have a reaction when it comes to doing my whole head. Maybe I might hedge my bets with 24hrs...

I think the thing to remember with allergies is that it can be your body that changes. So it is possible that you have been in contact with a substance that has sensitised you - henna tattoos are famous for doing this with hair dyes, and the box will specifically mention those, for example.

It would be very bad luck for sensitisation to occur in the 48 hours between patch test and dyeing, and in fact I am not sure it would be long enough to do so as your immune system would need time to build up the sensitisation.

All that said, I have never bothered with a patch test, despite knowing someone who is now unable to use any hair dye ever again because of a sudden very strong reaction.

despite knowing someone who is now unable to use any hair dye ever again because of a sudden very strong reaction.

That frightens me🙉...I tried going gracefully grey and hated every minute of it, couldn't cope with not being able to use hair dye. I have actually hennaed for most of my life ( been grey since my twenties), but the grey now takes on too much Red.