Allergies on Skin
Most of us have bumpy, itchy, scaly, or red skin at some point in our lives. One of the most common culprits? A skin allergy.
That’s when you encounter something your body thinks is dangerous, called an allergen. Your immune system overreacts and releases antibodies to fight off these “invaders.” This causes a variety of skin allergy types.
Skin Allergy Types
Skin allergies come in different forms. Here are the most common types:
Contact dermatitis
If you’ve ever gotten a rash after wearing a new ring or using a different soap, you’ve probably had this condition.
What causes contact dermatitis? It happens when your skin touches an allergen, like nickel or a chemical in a soap, lotion, or sunscreen.
Particles in the air, such as pollen, can also trigger dermatitis when they land on the skin. Your doctor may call this “airborne contact dermatitis.”
In some cases, you’ll have a reaction only after you’ve been in the sun. This is sometimes called “photoallergic contact dermatitis.” It’s brought on by a reaction between ultraviolet rays from the sun and some chemicals, such as those in sunscreens, shaving lotion, and perfumes. Medications, including some antibiotics, can also cause this rash.
Contact dermatitis symptoms. Symptoms range from mild to severe. They include:
- Redness
- Swelling
- Cracking
- Burning
- Blisters
- Bumps
- Scaly patches
- Rashes
You usually don’t get a reaction right away. It can take anywhere from a few hours to 10 days. Typically, it takes from 1 to 3 days.
Hives
These are raised, itchy red welts or bumps. Hives can show up anywhere on your body, including your face, chest, back, arms, or legs.
What causes hives? Contact dermatitis can trigger them, but allergic reactions to insect bites, medications, and foods can also bring on a reaction. You can also develop hives from a viral infection, stress, or after exercising.
Hives symptoms. Raised, itchy welts is the most common symptom. Rarely, more severe symptoms can happen, such as:
- Coughing
- Shortness of breath
- Closing of the throat
- Swollen tongue
Hives tend to appear right away, and they fade within a few hours or days. They can be a few millimeters or up to several centimeters large.
Eczema
You may hear this called “atopic dermatitis.” It’s a chronic allergic condition that usually begins in childhood. About 30% of Americans have it.
What causes eczema? Experts aren’t certain what leads to it. They do know certain triggers can make your skin itchy, red, and dry. They include:
- Animal dander
- Cleaning products
- Dust
- Food or seasonal allergies
- Asthma
Eczema symptoms. Symptoms can be different for each person. Infants and young children usually have eczema on their face, knees, or outside of their elbows. Older children and adults tend to have symptoms on their hands or feet, arms, or behind their knees. Symptoms can include:
- Dry skin
- Scaly patches
- Swelling and redness
- Small red bumps
- Oozing of liquid onto the skin
- Thicker skin
Eczema symptoms, called flare-ups, can last for several days to weeks.
Swelling
This is sometimes called angioedema. It means an area of your skin is raised or enlarged, often in soft tissues like the eyelids and mouth. Swelling can happen along with hives, but not always.
What causes swelling? It's often unclear why swelling happens. Food allergies, animal dander, pollen, and insect bites can cause swelling. It can also happen because of allergies to medicines like antibiotics, aspirin, ibuprofen, or blood pressure medications. Autoimmune disorders like lupus may cause swelling. In rare cases, swelling can happen because of a genetic disorder called hereditary angioedema (HAE).
Swelling symptoms. Symptoms can last for a few minutes to hours and often come with symptoms that aren't skin-related. They include:
- Sudden swelling below the surface of the skin
- Skin-colored welts or raised areas on the surface of the skin
- Stomach cramps
- Trouble breathing
- Swollen eyes or mouth
- Swelling in the lining of the eyes
Symptoms usually go away within a few days.
Skin Allergy Triggers
Narrowing down a cause can be tricky. There are hundreds of potential allergens.
Here are a few usual suspects.
Poison ivy, poison oak, and poison sumac. When parts of the leaves of these plants are damaged or bruised, they release an oil called urushiol. And if that gets on your skin, it causes an itchy red rash with bumps or blisters.
Nickel. It's used to make everything from jewelry to belts to eyeglass frames to paper clips. You're most likely to be at risk of a reaction if you have piercings, work with metal, or have a family history of nickel allergy.
Latex or rubber. The sap from rubber trees is mixed with a chemical and used to make products like:
- Rubber gloves
- Condoms
- Erasers
- Elastic waistbands and bras
- Balloons
You'll usually develop this allergy after being exposed to latex many times. Symptoms can be mild or severe, from itchy hives to trouble breathing.
Clothing. A rash on your chest after you wear a shirt, or on your feet when you wear certain shoes or socks, could be from an allergy. You might have a reaction after you try on a new outfit, too.
The trigger could be the dyes or other chemicals used to process the fabric (like making it wrinkle-resistant), or even the fibers of the clothing itself.
To avoid reactions, wash your new clothes before you wear them. You may also need to switch to cotton or organic cotton blends. You may want to avoid wool or mohair.
Preservatives. Chemicals called formaldehyde releasers and parabens make beauty products last longer. You'll see them on labels with names like bromonitropropane, diazolidinyl urea, isothiazolinone, PABA, and quaternium-15. They're found in:
- Shampoos and conditioners
- Sunscreens
- Lotions and moisturizers
- Makeup
- Hair dye
- Fake tattoos
Try mild soaps, and skip anything that causes a rash.
Fragrances. These are the heart of perfume, cologne, and deodorant. They're added to face and body soaps. They're also used in cleaning products and to mask a bad smell.
It's hard to pinpoint a fragrance allergy because specific ingredients aren't always written on labels. Even "unscented" and "hypoallergenic" products could have a bit.
Medications. Some ingredients in over-the-counter creams and ointments might make your skin problems worse. Look for these drugs on labels for products that treat cuts, scrapes, burns, itching, insect bites and stings, cold sores, toothaches, and earaches, as well as cough drops:
- Bacitracin
- Benzocaine
- Diphenhydramine
- Hydrocortisone
- Neomycin
Ultraviolet light. You may get a rash or hives if you’re sensitive to the sun, or if you've used certain products or combinations of them on your skin, and then go outside in the sun or use a tanning bed. This isn't a sunburn, but it can look like one.
How Long Do Allergic Reactions Last?
Allergic reactions can last for only a few hours or up to several days or weeks. It may depend on how much time you spent near whatever triggered your reaction. For some people, allergies last a lifetime, but other people outgrow allergies.
Skin Allergy Treatment
Treatment depends on the type of skin allergy and what caused it. Start by avoiding contact with anything that triggered your reaction. Here are treatment options for different skin allergy causes:
Poison ivy, poison oak, and poison sumac. You can treat the rash with wet compresses, calamine lotion, oatmeal baths, or hydrocortisone cream. But see a doctor right away if your reaction is severe or if you breathed in the oil, perhaps from burning plants. Also call your doctor if the rash is on your face or genital region, if it looks infected, or you have a fever.
Nickel. There's no cure for a nickel allergy, so you'll have to stop wearing or using anything with it. To prevent a reaction, you could try painting a coat of nail polish on jewelry, which puts a barrier between the metal and your skin. If your reaction is severe, your doctor may prescribe a steroid or nonsteroidal cream, or an antihistamine to stop itching.
Latex or rubber. If your reaction is mild, you may need a prescription for an antihistamine or a corticosteroid to bring down swelling. A severe reaction, called anaphylaxis, might quickly spread throughout your body and make it hard to breathe. Carry injectable epinephrine (adrenaline) to protect yourself, or go to the emergency room.
When to see your doctor about skin allergies. Skin allergies can become serious. Here are signs that you should see your doctor:
- A rash that covers most of your body
- Blisters, open sores, or raw skin
- A fever or a sick feeling, along with a rash
- A fast-spreading rash
- A painful rash, or one that affects your eyes, mouth, lips, or genital skin
- Swollen lymph nodes
- Trouble breathing or swallowing
How Can I Prevent a Skin Allergy?
The best way to avoid that rash is to steer clear of the allergen. Your doctor can help you figure out exactly what the cause of your allergy is.
You may get an allergy scratch test in which tiny amounts of allergens are put on your skin. You’ll be asked to keep that area dry. After a few days, those areas are checked to see if you get a reaction.
If you do touch a potential allergen, wash the area with soap and water as soon as possible.
