Formaldehyde is a chemical that is often used as a preservative in medical labs and funeral homes. It may also lurk in your makeup, and it can cause allergic reactions. It is one of many ingredients used in beauty products that you can be allergic to.

Dry makeup, like powder or brow pencils, requires fewer chemicals and tends to cause fewer allergies.

Allergy Categories

There are four types of allergic reactions, also known as hypersensitivities. Type I allergies are the most severe, and type IV allergies are the least severe. Makeup allergies are a type IV allergy.

Makeup allergies only affect the area of your skin where you apply the product. For instance, if you are allergic to an ingredient in your eyeshadow, you may have swollen and puffy eyelids. Symptoms will be limited to your eyelids, and will not affect the rest of your body.

Also, you may not have symptoms right away. "The longer you use a product, the more likely you are to develop an allergy to it," says Dr. Liszewski.

Allergy or Irritation?

Some ingredients in beauty products, like retinol, may sting your skin. But, this may not mean that you are allergic to them.

• Allergies may cause swelling.
• Irritation often involves stinging or a rash.

"People often think a sense of burning, stinging or tightness is evidence that a beauty product is effective. This is not true," says Dr. Liszewski. "Many products can be irritating. If a product makes you feel pain, it's best to avoid it, use a lower concentration of the product, or apply it less frequently, such as every other day."

The "Hypoallergenic" Myth

"'Natural,' 'clean' and 'hypoallergenic' are meaningless terms on beauty products. You can still be allergic to hypoallergenic products," says Dr. Liszewski. "Just because something is labeled clean or hypoallergenic doesn't mean that it is safe for your skin. In fact, products labeled as clean or organic are often more irritating than products that primarily use synthetic ingredients."

When to See Your Dermatologist

If you keep getting rashes from personal care products and cosmetics, contact your dermatologist. They can figure out if your rashes are due to allergies or other skin issues, such as atopic dermatitis (eczema), seborrheic dermatitis or facial dandruff.

Your dermatologist will work with you to simplify your beauty routine. The fewer products you use, the less likely you are to have a reaction. Your physician may do patch testing, a type of skin allergy testing, to learn what is causing your swelling and irritation.

The next time you have skin symptoms, take a picture to show your dermatologist. They may prescribe topical steroids to treat your reaction.

"Makeup allergies are common, but if you are allergic to a product, do not use it again," says Dr. Liszewski. "If you are looking for products that agree with your skin, reach out to a board-certified dermatologist for guidance."