It can be difficult to identify the difference between an irritation/sensitivity and an allergy because symptoms can look very similar. Both can show signs of the following:

  • Itching

  • Swelling/puffy eyes

  • Watery eyes

  • Eyes feel tight

  • Eyes burn

So, what is the difference?


Irritants/sensitivities do not cause the immune system to react unlike an allergy. Irritants will usually subside after 24 hours, whereas reactions can appear days, weeks or even months after exposure.

Eyelids can be very prone to irritation as the skin here is much thinner than other parts of the body, thus making them venerable to any products used on or near them.


An allergy is much more serious than an irritant and is caused by body’s immune system responding to the allergen and trying to fight it.  The body produces antibodies (or immunoglobin) to fight these allergens and typical symptoms can affect the eyes, nose, throat, skin and in severe cases can cause anaphylactic shock.

For an allergy to develop, you have to be exposed to the allergen more than once and repeatedly. This means that it is very rare for a client to react to eyelash extensions if she has never worn them before, however over several months/years, she could then suddenly react to the extensions and no longer be a candidate for them.

While a small percentage of clients will develop an allergic reaction, this allergy is not especially dangerous in most clients, and any symptoms will disappear once the extensions are removed.

However, the human body is very clever and never forgets, therefore if the client is exposed to the same product in the future the body will continue to react – it does not simply forget!

What are clients reacting to…

What is cyanoacrylate (CA)?

The main ingredient of lash adhesives is a cyanoacrylate which is the stuff that makes the glue sticky and cures extremely quickly. CA is used in all eyelash adhesives, even “sensitive” adhesives, but is present in much lower levels.

The general belief is that most clients that react to Eyelash Extensions are reacting to the CA, however research over the years has led us to believe that this may not be the case. Instead clients maybe sometimes be reacting to the black carbon (if your client cannot wear black mascara, eyeliner etc), or more likely they are reacting to the stabilizers used in the adhesive.

However, unless that client gets independently “allergy” tested, we can never really know – and this is why on some occasions a client that has shown an allergic reaction to one adhesive has been able to wear another – contrary to the belief that if you are allergic to Eyelash Extension adhesive then you will be allergic to all.

However, unless that client is independently tested to identify exactly what product they are allergic to, you cannot take the risk and simply keep trying different adhesives.

How do I stop my clients being sensitive or allergic to Eyelash Adhesive?

Although lash adhesives are widely used, not all are safe, with many being produced outside of the EU where safety regulations can fall short – and as such can pose potential health risks to clients. The use of additional stabilizers in most cases will cause adhesives to fall into the category of unsafe and as such most glues produced outside of the EU will not pass the EU regulations which supersede those across the globe.

To limit reactions, ensure that you purchase your glues from companies inside the EU and who can provide evidence that their glues are safe and meet strict EU regulations.

However, despite using safe glues, some clients can still react. If there is any redness or itching after patch test, the client is considered high risk and lash extensions are not recommended. Sadly, the amount of adhesive used at a patch test is very small, therefore it doesn’t guarantee that the client will be fine, therefore, it is important to inform your client of any possible contraindications and allergies that may occur as a result of having eyelash extensions.