Skin allergies are no fun, especially when they last several days or weeks. I’ve had my fair share of rashes and other skin issues. It can be frustrating trying to get rid of the skin allergy.
How long does skin allergy last? Skin allergies usually last about 2 to 3 weeks. If your skin allergy is hives, it can last a day or two. If you have an eczema flare-up, it can last from several days to several weeks.
The reason you have a rash is because your body overreacted to something it thought was dangerous. It was actually trying to help you but went overboard and created the rash.
When the skin suspects something dangerous is attacking it, it releases antibodies to combat the attackers. This creates the rash.
Read on to learn what type of skin allergy you have and how long it will last. Also, I’ll give tips on how to get it to clear up faster.
How Long Does Skin Allergy Last?
There are many different types of skin allergies and allergic reactions. Below, I’ll cover contact dermatitis, atopic dermatitis, and hives. To know how long your skin allergy will last, let’s first determine what type of skin allergy you have.
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Dermatitis is a fancy medical term for skin rash. It is defined as a condition of the skin in which it becomes red, itchy, and swollen.
There are thousands of causes of contact dermatitis.
For example, air particles such as pollen or dust can also cause contact dermatitis, or more specifically, “airborne contact dermatitis.”
A skin allergy caused by chemicals in sunscreen or a lotion being exposed to the sun is called “photoallergic contact dermatitis.” Contact dermatitis skin allergy usually lasts from 2 to 3 weeks.
Atopic Dermatitis (Eczema)
Eczema’s medical term is atopic dermatitis. Unlike contact dermatitis, atopic dermatitis may occur on skin that never came in contact with an offending object.
Eczema is a red, itchy, dry skin rash that mostly affects children (10-20% of American children), often newborns, in the first few months after birth. It often improves as the child grows, but many still battle with it into adulthood (1-3% of American adults). It can also start in adulthood.
The skin barrier that is normally water-tight becomes weak. This broken barrier lets moisture out and lets irritating, toxic elements in. This leads to infection and the need to constantly moisturize to protect the skin.
Eczema is a chronic condition meaning that the person with atopic dermatitis has it for life; however, they can manage it to the point where there are little to no “flare-ups.”
If you have had a skin allergy for longer than a week and/or you are scratching it as it has a burning red itch, it is important to see a doctor. The doctor can prescribe a steroid cream.
Hives, also known as urticaria, is a skin rash with itchy, red, raised, swollen, often burning bumps.
Hives can be brought on by contact dermatitis (one of the many causes, as explained earlier); however, hives are most commonly caused by a reaction to eating something, taking a certain medication, or an insect bite.
Other possible triggers could be cold temperature or being stressed. The cause is unknown in about 50% of hives cases.
Unlike contact dermatitis, hives often appear right away or within a few minutes.
How long does skin allergy last when it results in hives? Hives usually lasts for a day or two. Less than 5% of hives cases last longer than 6 weeks. 
More Info on Contact Dermatitis
Contact dermatitis is a type of eczema, and it is the result of something coming into contact with your skin, as the name implies. The contact with the offending object causes an immune system response. The immune system response leads to an itchy red rash in the location of contact.
Almost anyone can develop contact dermatitis. Some rashes will happen right away; however, most take some time to appear – up to two to three days.
What is pretty confusing is when you’ve been using a skincare product for a while and then have an allergic reaction to it. People may say that they’ve been using this product for many years and never had a problem with it.
Allergic Contact Dermatitis
You may be loyal to a certain skincare brand, and then all of a sudden, your skin is going berserk. You may be quick to dismiss the product, but it could be the culprit because you’ve been using it for so long.
You may have developed a sensitivity to an ingredient in the skincare product. This is not uncommon. This type of contact dermatitis in which you become sensitized to an ingredient or an allergen is known as allergic contact dermatitis.
This is a skin rash that is a manifestation of an allergy to an antigen or an allergen present in something that is coming in contact with your skin, whether that be a cosmetic or some sort of plant from the environment. I think a classic example of allergic contact dermatitis that we may all be familiar with is poison ivy.
So allergic contact dermatitis is from coming in contact with something you have become sensitized to and are now subsequently allergic to. Contact with this item will make your skin red, itchy, and dry. Next, let’s look at a different type of contact dermatitis.
Irritant Contact Dermatitis
There is also another type of contact dermatitis called irritant contact dermatitis. Irritant contact dermatitis is even more common than other allergic reactions.
It is a type of skin rash that, like allergic contact dermatitis, results in a rash after something has come in contact with the skin. However, unlike other allergic reactions, this does not involve the individual becoming sensitized to an ingredient.
It’s not uncommon also to experience irritant dermatitis quickly at the beginning of exposure, and then allergic dermatitis could develop on top of that if you continue exposure.
Allergic dermatitis usually causes a rash after a few days, slowly and gradually. Irritant dermatitis rashes develop quickly. But you could get both.
What Allergens Are Common Causes of Contact Dermatitis?
I’ll now go over some common causes of allergic contact dermatitis.
I already mentioned what everyone is familiar with, such as poison ivy as well as nickel, but for many wondering what things to avoid in skincare products, I think it’s most relevant to address the common allergens that are found in many cosmetics and over-the-counter skincare products and makeup, etc.
I’m often moaning about the shortcomings of fragrance added to skincare ingredients. Fragrance allergy is probably one of the most common, and I always caution you to err on the side of caution and select products that are fragrance-free.
It is common for people to have an allergic reaction to fragrances, such as an allergic skin reaction or other allergic reactions.
Also, read carefully the term “free of synthetic fragrance” because natural fragrances can also be problematic. It is not uncommon for people to develop allergic contact dermatitis to essential oils.
They’re very popular in skin care right now; however, our immune system does not like us putting them on our skin.
The next cosmetic that frequently causes an allergic reaction is a makeup remover. Makeup removers often contain certain preservatives that people frequently can develop an allergy to. They’re problematic because the longer these ingredients sit on the skin, the more likely an individual develops an allergy to them.
One common preservative found in makeup wipes, or baby wipes, for example, is something called methylchloroisothiazolinone. Try to say this 3 times fast! It is a long name. You may hear it referred to as MCI. This is not a dangerous ingredient.
It’s not associated with any serious side effects or any true cancer risk. It is not a demon ingredient. It’s safe, but when left on the skin – products containing it – it can result in an allergic reaction such as allergic contact dermatitis.
That’s a real risk with using MCI. Skin allergy caused by makeup remover can last a week or more, so it is best to get a natural, irritant-free makeup remover that works with your skin.
Other Possible Allergens
Parabens can be problematic but are safe otherwise. Lanolin is another ingredient that is commonly found in moisturizers. It is derived from sheep and is common in products like lip balm.
It’s soothing, it’s an emollient, but it’s not uncommon to develop an allergy or immune system response to lanolin. There are other allergens found in nail polishes and shellac and nail hardeners—things like formaldehyde and acrylate cyanoacrylate.
Those are some of the most common things that cause an allergic reaction, such as allergic contact dermatitis. What about irritant contact dermatitis? If you recall, irritant contact dermatitis is not an allergy but rather the result of the substance just plain being irritating on the skin.
See a Dermatologist for a Patch Test
If you haven’t figure out on your own what is causing the issue, then it is best to see a dermatologist for evaluation and management. They will ask you to bring in your potential offending products and examine the rash that you have and your products.
They can perform something called patch testing, which is the way to diagnose allergic contact dermatitis. Patch testing is very different from allergy testing that an allergist would do.
Patch testing for allergic contact dermatitis that a dermatologist would perform involves putting on patches of little wells on your back. Each of the wells contains some of the culprit allergens like fragrance, for example. These patches stay on your back for 48 hours when they are removed.
After all the readings are complete, the health care provider puts all the information together and comes up with a conclusion to help you identify what it is that you’re coming in contact with that you’re having an allergic reaction to.
They then put together their recommendations for how to avoid that product and keep your immune system protected.
Skin allergy usually lasts about 2 to 3 weeks. Contact dermatitis can last about 2 weeks, and Atopic dermatitis can last much longer, up to several weeks.
If you have hives, it often only lasts for a couple of days. Of course, avoid whatever you came in contact with to cause the allergy.
If you are unsure what caused it and it is bothering you or lasting too long, then go see a doctor or dermatologist. You can get a patch test done to test different substances that could be the cause of an allergic reaction.
I hope this post gives you more reassurance on how long you can expect to have an allergy or rash. Whatever it turns out to be, I do really hope the skin allergy doesn’t last long.