/
Skin Problems & Cosmetics
/
About Allergies
About Allergies
What is an allergy?
Spring hay fever or hives after eating certain foods… these are just some common allergic reactions.
Allergies are caused by an “antigen-antibody reaction” where the body tries to eliminate foreign substances (antigens or allergens). This occurs when the immune system’s response—which is normally essential for the body—becomes excessive and harmful.
Allergies are classified into types 1 through 4. Type 1 (immediate type), where symptoms appear within about 10 minutes, often causes hay fever, hives, bronchial asthma, and allergic rhinitis.
Type 4 (delayed type), where the reaction occurs after some time, is known as allergic contact dermatitis (rash).
Why do I get a rash from makeup?
The causes of a "cosmetic rash," which is a general form of contact dermatitis, can be broadly divided into two categories: "irritation" and "allergy."
Irritant Contact Dermatitis
This is dermatitis caused by irritation (toxicity) resulting from skin contact. For example, most people will experience symptoms if the irritation from alcohol, concentrated acids, strong alkalis, or friction exceeds a certain level.
Point
The severity of an irritant rash depends on your skin condition at the time. For instance, symptoms often occur when your skin is weakened due to your physical health or the season, when the skin barrier is compromised, or when the skin is damaged from hair removal or other causes.
Allergic Contact Dermatitis
This dermatitis occurs when antibodies in the body try to eliminate a foreign substance (allergen). Even if the concentration or amount is very small, symptoms appear only in individuals who have a specific reaction to that substance.
Point
An allergic rash can occur regardless of your skin condition at the time. Even after symptoms improve, if you come into contact with the allergen again, the same allergic reaction may recur.
In both cases, symptoms are similar, including redness, itching, heat, and swelling. However, identifying whether the cause is irritation or an allergy is very difficult, so we recommend consulting a dermatologist.
What should I do if I get a rash from cosmetics?
Stop using the product and see a dermatologist for proper treatment.
Initial first aid includes using a mild soap to wash the cosmetics off the skin and applying a cold compress if it feels hot. However, relying solely on these traditional remedies may worsen the condition. You should visit a dermatologist for appropriate medical care.
Point
During a medical consultation, it is important to explain as clearly as possible when it happened, under what circumstances, and what the symptoms were.
Even if symptoms subside, there is a risk of recurrence if the cause remains unknown.
Checking which products worsen the condition and which ones work for you individually will help identify the cause.
Some dermatologists also use a method called “patch testing” to identify the substance causing the rash.
What is a patch test?
A patch test is a method used to identify the substance causing a rash. The most common method used in dermatology is the "closed patch test." First, a bandage containing the suspected substance is applied to a flat area of the back for two days. During this time, you can wipe your body, but you must not bathe. After removing the bandage, reactions are monitored two days, three days, and one week later. It is often thought that allergens cause an immediate reaction, but it can take several days for the antigen-antibody reaction that causes an allergy to occur in the body. For this reason, the reaction is tested three times over a period of time.
Be careful not to develop a rash
The first thing to do is avoid contact with the allergen. If the allergen can be identified, you can prevent cosmetic allergies by avoiding that specific ingredient.
Currently, all ingredients are listed on cosmetic containers and outer boxes, so you can check if your product contains any known allergens.
However, ingredient names can be written in various formats, so please check with the manufacturer for details. (In April 2008, the Cosmetic Industry Association began requiring ingredient labeling for quasi-drugs according to its own standards.)
A simple test you can do yourself
Even if you avoid known allergens, there are still cases where a cosmetic product might not suit your skin when you actually try it. Here, we introduce a simple "usage test method."
Usage Test Method
The soft skin on the inside of the arm responds most effectively to allergens.
Using clean hands, apply a small amount of the cosmetic product (about the size of a 100-yen coin) to three spots as shown in the illustration.
*Facial cleansers, soaps, shampoos, etc., should be lathered with water, applied for 1-2 minutes, and then rinsed off. You can bathe during this time, but do not scrub the inside of the arm where the product was applied too hard. Observe for about 4 days, and if there are no abnormalities, you can use it on your face.
What are the most common causes of makeup rashes?
The most frequently reported substances include fragrances, food coloring, lanolin alcohol (an emulsifier), hair dyes (PPDA), and metals. These substances are found not only in cosmetics but also in food, medicine, clothing, etc., so please be careful in your daily life.
Metal Allergies and Cosmetics
Do you often experience redness or itching when you sweat? While sweat itself can be a cause, it may also be due to metals dissolving in the sweat. Even if the metal is not a problem in its solid state, dissolving in sweat can cause issues for those with metal allergies.
Causes of Metal Allergies
When thinking of metals you wear, jewelry is the first thing that comes to mind. Metal allergies are often caused by impurities such as cobalt, nickel, and chromium. Therefore, the lower the purity of the metal —such as plated metal—the more likely it is to cause an allergic reaction. Besides jewelry, other leather products like watch straps and bag handles can be a cause, as chromium is used in the tanning process to give leather its shine. Additionally, metal allergies can occur from dental fillings used in treatments.
Metals in Cosmetics
Cosmetics and metals may seem unrelated, but iron oxide, used as a pigment in cosmetics and sunscreens, actually contains trace amounts of metal impurities such as cobalt, nickel, and chromium. Therefore, if you experience redness, itching, or other rashes after applying makeup or sunscreen, it is possible that you have a metal allergy. Furthermore, if you already know you are allergic to metals, you should be extra careful when choosing cosmetics.
Q on Allergy Management
I feel irritation and itching no matter what product I use. Could I be allergic to cosmetics?
It is very rare for someone to be allergic to all types of cosmetics.
If you experience irritation from every cosmetic product you are currently using, stop using them immediately, including makeup.
If symptoms persist, consult a dermatologist, as the cause may not be related to cosmetics at all.
Tips
Regardless of whether the rash is caused by cosmetics, using them while experiencing redness and itching can trigger an allergic reaction.Even if the cosmetic is normally suitable for your skin, it can worsen the condition.
The same applies if the natural skin barrier is damaged from excessive massaging or washing. Therefore,to determine which cosmetics are right for you, the first priority is to soothe the symptoms.
My redness and itching are getting worse. Is it because of cosmetics or is it atopic dermatitis?
The symptoms of a cosmetic rash and a flare-up of atopic dermatitis (*) are very similar, so in this case, both are possible. It is important to stop using cosmetics first and let the skin rest.
If symptoms improve immediately, cosmetics may be the cause. On the other hand, if symptoms do not improve over time, it is possible that atopic dermatitis is worsening. We recommend seeing a dermatologist for a proper diagnosis.
Tips
To help treat atopic dermatitis, skin care that incorporates the concept of (Skin Control) = (Cleanliness) + (Moisturization) is extremely important. However, this applies only during the remission phase* when the skin condition is relatively stable.
When symptoms flare up, even cosmetics that normally don’t cause irritation can become a problem.
Please consult a dermatologist before using cosmetics.*Exacerbation phase: The stage where atopic dermatitis symptoms worsen, causing itching and rashes.
*Remission phase: The stage where atopic dermatitis symptoms subside and the skin becomes stable.
I was told I have an allergic reaction to fragrances in cosmetics. My symptoms improved after treatment, but should I stop using cosmetics altogether?
Once you have an allergy, the sensitivity usually lasts a lifetime.
Even after symptoms subside, you should avoid using cosmetics containing the fragrance that caused the reaction.
Even if your skin condition improves with treatment, if you are exposed to the allergen again, the same symptoms will return and your skin condition will deteriorate suddenly. However, it is too early to conclude that all cosmetics are harmful.
Tips
If the cause of the allergy is unknown, you can use cosmetics just like someone with healthy skin, as long as you avoid contact with the specific substance. For example, if you are allergic to fragrance, you can use fragrance-free cosmetics.
In other words, it is important to understand the “allergen” that causes your reaction and how to avoid it in your daily life.
Keep this in mind not just for cosmetics, but for your daily routine as well.
Is it true that people often get cosmetic rashes during allergy seasons, like hay fever season?
Yes, that’s true. When you have allergies like hay fever, the moisture content in the skin’s keratin layer decreases.
This makes the skin dry and significantly weakens the skin barrier. You may become more sensitive to irritants than usual.
During this time, cosmetics that normally don’t cause a reaction might become irritating or trigger an allergy.
If you are trying a cosmetic for the first time, it’s best to wait until your hay fever symptoms subside.
You choose cosmetics from a wide range of products. It would be a shame to conclude that a product is “not suitable” for your skin just because of the effects of hay fever, when it might actually be a good fit. To find the best products, try them when you are healthy and less prone to allergies.
From the Handbook for Allergy Sufferers with Sensitive Skin (Edited by Dr. Hideo Nakayama)
