What is A Skin Allergy?
The word skin allergy is often incorrectly used to mean “skin rash”. A true allergy occurs when you are re-exposed to an allergen (called an antigen). Skin allergy does not occur the first time you come into contact with the antigen. You form IgE antibodies and then the next time you are exposed, you have an allergic rection.
This is why you may use a skin care ingredient many times without a problem and then suddenly develop an allergy to it. Skin allergy is not the same thing as skin irritation. Skin allergy is medicated by IgE antibodies in your immune system. Skin irritant reactions do not involve IgE antibodies.
When your immune cells recognize the allergen that you have been previously exposed to, IgE antibodies get involved and cause skin inflammation. Inflamed skin occurs mainly due to a release of histamine from mast cells. This is why antihistamines are used to treat skin allergies. Histamine causes activation of many inflammatory pathways in the skin and dilation and leakiness of blood vessels leading to redness, swelling, and itching.
The inflammation seen in allergic skin rashes increases the production of melanin pigment leading to pigmentation and a disorder called post-inflammatory hyperpigmentation. (PIH) This is why darkening of elbow and knee skin is often seen in patients with eczema.- especially those with skin of color.
Science of Skin Allergies[i]
When a mast cell armed with IgE antibodies is re-exposed to an allergen, multiple responses occur, leading eventually to the release of various potent mediators responsible for the clinical expression of immediate inflammatory-hypersensitivity reactions that is commonly called “an allergic reaction” or “hives”.
In the first step of this sequence, antigens bind to the IgE antibodies previously attached to the mast cells. The bridging of IgE molecules with the underlying IgE-Fc receptors activates signal transduction pathways that will translate into three outcomes:
1) Degranulation allowing secretion vasoactive amines (histamine), proteases (chymase, tryptase, hydrolase), and proteoglycans (heparin, chondroitin sulfate).
2) Synthesis of pro-inflammatory lipid mediators (Leukotrienes C4, D4, and B4, and Prostaglandin D2)
3) Synthesis and secretion of cytokines and chemokines
Once these pathways get turned on - other inflammatory pathways can be activated. It is a domino effect. Inflammation causes more inflammation.
Skin Allergy Treatment-
Skin allergies are treated with removal of exposure to the allergen. You must figure out what you are allergic to. Once you know what you are allergic to- you must read every skin care label to make sure the product does not have the ingredient that you are allergic to in it. If you do not know what you are allergic to- try this hypoallergenic skin care brand.
You can treat skin allergy with antihistamines (such as diphenhydramine), corticosteroids and other anti-inflammatory ingredients.
Our recommendations on the best products for allergic skin are found below. Make sure they do not contain anything you are allergic to in them before using. We are working on a way to recommend skin care products to you that do not have anything in it that you are allergic to, but first we have to collect more data. This is why we ask you in the skin type quiz what you are allergic to. For now, you must read the product label yourself to make sure the product does not have anything YOU are allergic to.
What is the Best Skin Allergy Cream?
There are many prescription corticosteroids used to treat skin allergies. Hydrocortisone is the only corticosteroid cream you can get in the USA without a prescription.
Topical creams using anti-inflammatory ingredients to soothe and calm the skin are also used. Many of these have botanical ingredients that are allergens and can make the skin allergy worse.
These soothing barrier repair creams soothe skin and help protect skin from allergens
Best Soothing Natural Oils To Treat Skin Allergy
This is the best organic oil to treat skin allergies:
Cleansers that do not have strong detergents and contain anti-inflammatory ingredients and soothing fatty acids should be used to calm allergic skin. Here are some choices but remember- check the label before buying:
How To Find Out What Is Causing Your Skin Allergy
It is important to identify what you are allergic to in order to properly treat skin allergies. You can either:
- Keep a diary of what you were exposed to in the 6-12 hours prior to a skin allergy rash
- See your dermatologist for patch testing.
[i] This material is adapted from Anti-inflammatory Ingredients in Ch. 38 of Baumann’s Cosmetic Dermatology (McGraw Hill 2022)