How to Patch Test Skincare?
Anytime you introduce a new skincare product to your routine, you're introducing a new formula that could benefit your skin, but it can also potentially irritate it. Even when you’ve a pretty firm grasp of what works for your skin, no two products are the same. In comes patch testing skincare; an essential first step to incorporating any new product to your regime.
In this article, we’ll run down the importance of patch testing your skincare, how to patch test at home, and common ingredients that can cause reactions. Read on.
What is a patch test?
A patch test involves applying a skincare product or specific ingredient to a small area of skin to test your skin’s reaction. Patch testing helps to identify skin allergies and sensitivities to determine what products are suitable for ongoing use. Any skincare product can cause a reaction, including face wash, moisturisers, serums and face masks.
Why should I patch test my skincare?
Patch testing skincare allows you to determine whether certain ingredients may cause irritation. Applying to a small area helps determine your skin’s tolerance before you apply product over a larger surface area. Patch testing helps to:
● Identify the skin's tolerance to certain active ingredients.
● Test out a new skincare product before purchasing.
● Prevent skin irritation or adverse reactions to skincare.
● Tailor your skincare routine and maintain your skin's condition.
When should I patch test skincare?
You should patch test all new skincare products, especially if you have sensitive skin or are prone to allergic reactions!
How to perform patch tests at home
At-home patch testing is a good habit to keep if you're changing or adding to your skincare routine. Here’s a quick guide to patch testing skincare at home.
1. Apply the product to a small patch of skin
Avoid the facial skin; instead, apply to a part of the body that you're unlikely to wash or rub away the product (the inside of the arm or bend of the elbow are usually best).
2. Apply a thick layer of the product
Apply a generous layer of product—more than you would use regularly—to a small area, no more than a 20-cent sized patch.
3. Leave product on the skin for at least 12 hours
Leave product on the skin for as long as it would normally be on the skin—usually 12 hours but up to 24 hours.
4. Monitor for skin reaction
Monitor your skin throughout the day, then use a gentle cleanser to rinse off the product. If you have any adverse reactions, like skin irritation, redness or itching-sensations, rinse off product immediately and stop using it.
5. Repeat process
Patch testing for a couple days can often be enough to gauge your skin's reaction. But, depending on your skin type, you might want to repeat the patch test for a week or two, as some reactions might not happen immediately.
6. Gradually introduce to your skincare routine
If you have no adverse reactions, you can start adding the product to your regular routine! But make sure to continue monitoring your skin's response—especially for active ingredients like retinol, vitamin C or hydroxy-acids—as some reactions can develop over time.
Common ingredients that can cause reaction
Everyone’s skin is different, but there are some chemicals that are known to cause allergic reactions to sensitive and allergy-prone skin. In addition to patch testing new skincare products, check the label for the below ingredients:
● Fragrances (sometimes labelled as “parfum”) are often found in moisturisers and skin hygiene products can irritate all skin types. Look for skincare labelled fragrance-free or check for:
○ Linalool
○ Citral
○ Limonene
○ Citronellol
○ Geraniol
○ Benzyl alcohol
○ Benzyl benzoate
○ Diethyl phthalate (used to dissolve fragrance ingredients)
● Preservatives that might cause a reaction include:
○ Methylisothiazolinone
○ Methylchloroisothiazolinone
○ Parabens
○ Formaldehyde and formaldehyde-releasing ingredients
● Soaps, acids, solvents, and alkaline ingredients including:
○ Anthralin
○ Benzalkonium chloride
○ Tretinoin
○ Dithranol
○ Epichlorohydrin
○ Podophyllin
○ Propane sulphone
Choosing skincare for sensitive and allergy-prone skin
Skincare labelled hypoallergenic, organic, or suitable for sensitive skin, doesn’t guarantee you won’t react to a product. The best way to choose the right skincare product for sensitive skin is to identify what specific ingredients cause an adverse reaction and avoid them; and the best way to determine that is through patch testing!
When to consider professional patch testing
At-home patch testing can help determine your sensitivity to a certain product, but it can’t necessarily tell you the cause of the skin reaction. If you want to understand the cause of your skin sensitivity or irritation, it might be best to speak to a board certified dermatologist. A dermatologist can provide a more comprehensive assessment of your skin and skin sensitivities, and recommend suitable products.