Why do I need a patch test?

If you book in for a lash/brow tint or lash lift treatment, your technician should insist that you have a patch test at least 24-48hrs prior to treatment. What is often not fully explained to clients is why this is so important.

Some people are more prone than others to a skin reaction called contact dermatitis. This means their skin becomes red, dry and inflamed when they come into contact with a particular substance. Some substances are common irritants that are known to cause dermatitis in some people. Many permanent and some semi-permanent hair dyes and tints contain one such chemical called paraphenylenediamine (PPD). PPD is a known irritant and allergen and is the cause of most reactions to hair dyes and tints.

Most of us will tolerate PPD in tint with no problem at all but one university study carried out in Sweden found that 5% of those that took part reported some degree of adverse reaction.

There are varying levels of reaction to an irritant. A reaction may be just some localised dermatitis which can nevertheless be uncomfortable (itching/burning sensations) and unsightly (swelling, redness, broken skin and scabbing). At the other extreme, an irritant may cause a full on systemic allergic reaction which is much more serious. An extreme allergic reaction or anaphylaxis can cause a serious drop in blood pressure that can lead to organ failure. Anaphylaxis from hair tint is very rare but not completely unheard of.

Hair dyes and tints containing PPD are safe to use, providing safety instructions are followed. These products are strictly regulated and there’s a maximum limit to the amount of PPD the product can contain. If you ignore the safety instructions that come with the dye, you could put yourself at risk of a serious reaction.

All professional lash and brow tint products contain safety instructions that include details on how to perform a patch test prior to treatment. We are especially careful to patch test before lash and brow tinting as the product is being applied on or near to the delicate eye area where even a relatively mild, localised reaction could be quite distressing and lead to further complications such as eye infections. Much better that we test it first on your arm or behind your ear before putting it anywhere near your eyes.

The manufacturers of some treatments such as LVL recommend a patch test before every treatment, regardless of whether you have had the treatment before. This might seem a bit excessive if you have the treatment regularly but the reality is you can develop an intolerance to a common irritant quite suddenly and unexpectedly. This can be due to significant hormonal changes such as pregnancy or menopause, illness or prescription medication or for no apparent reason at all. Many things can potentially cause changes to the way your immune system responds to a potential irritant.

If your technician is not following the manufacturer’s guidelines regarding patch testing, in addition to putting you at risk of a reaction, it will also invalidate their insurance and rightly so.

I know it’s a bit of a bore but patch testing; definitely so much better safe than sorry.