Allergy Rash: Causes & Management

Allergy Rash: Symptoms, Causes, and How to Manage Them

An allergy is your body’s reaction to a foreign substance that is usually harmless in nature, like animal fur¹. Skin allergies can lead to an allergy rash, which can present as red, bumpy and itchy skin².

Here, we‘ll help you learn about the different types of rashes you could get from an allergic reaction, and the different skin rash allergy treatments available.

In this guide:

What is an allergic rash?

An allergy rash occurs when your body encounters something that it perceives as dangerous². This substance is called an allergen and it’s what triggers an allergic reaction³. This can include things like pollen, pet dander, and dust¹.

Your immune system reacts by releasing antibodies to try and defend against the allergen. This reaction may lead to a variety of allergy symptoms, including skin rashes².

Different types of skin rashes caused by allergies

There are different types of skin allergies but they generally fall into three main categories:

Hives

Hives, also known as urticaria, is a sudden outbreak of pale red welts or bumps on the skin. This outbreak is often accompanied by swelling⁴. Urticaria is common, affecting about 20 per cent of the population at some point in their lives⁵.

There are different types of urticaria, and it can be categorised as acute or chronic⁵. In acute urticaria, the hives last less than six weeks, while in chronic urticaria, the hives can last longer⁵.

Hives can appear as raised, reddish welts of varying sizes on the skin⁴, and can feel itchy, sting or burn⁵. They may be spread over one area or appear anywhere on the body⁵. They can come and go in minutes or stay for hours⁴.

Eczema

Eczema, also known as atopic dermatitis, is a common skin condition that causes the skin to become dry, itchy and cracked⁶. In some cases, it can cause the skin to become sore and inflamed. It can appear reddish on pale skin, and purple/brown on dark skin⁶.

Allergens are a common eczema trigger⁶. It can affect any part of the body but is most common on the knees, scalp, cheeks, hands, area around the neck, and inside or outside of the elbows⁷.

Contact dermatitis

Contact dermatitis is a rash that usually appears when you encounter a substance that you’re allergic to (allergen). This can be anything from using a different bar of soap to air particles like pollen landing on your skin².

Symptoms of contact dermatitis can range from mild to severe², and may include a rash that’s red, itchy, burning and uncomfortable⁸. Scaly patches may also be visible². Contact dermatitis can appear anywhere on the body, but usually occurs on parts of your body that have come into contact with the allergen⁸.

Common triggers for a skin allergy rash

Knowing the exact cause of your allergy rash can be tricky, as there are more than 3,700 potential allergens that could cause your allergic reaction². However, some of the most common triggers include:

• Pollen. Plants, such as oak trees, grasses and ragweed, produce a fine powder called pollen as part of their reproduction process, which can easily travel through air⁹. You can have an allergic reaction to pollen (hay fever) any time of the year. Seasonal allergies typically can occur in early autumn, summer or spring when pollen counts are high¹⁰.

• Pet dander. Pet allergies are caused by the protein present in your pet’s dander, urine, or saliva. Cats and dogs produce a lot of proteins which can cause pet allergies. Initially, it was widely believed that pet hair caused the skin allergies. However, it’s actually the dander (skin particles that they shed) that’s mainly responsible¹¹.

• Insect bites or stings. Insect bites and stings can cause an allergic reaction. In most cases, insect bites and stings can be treated at home. However, some people may go into anaphylactic shock, which requires immediate medical treatment¹². Call 999 if you’re experiencing symptoms of an anaphylactic shock, including a swollen lip, mouth or tongue, difficulty breathing or swallowing, tightness in the throat, a change in your skin colour, or sudden feelings of dizziness, drowsiness, or confusion.

• Latex and rubber. Certain chemicals are mixed with rubber sap from trees to make products like balloons, erasers, and rubber gloves. You might have a mild or severe skin reaction from using gloves or other products made from latex or rubber².

• Some medications and cosmetics. Some chemicals in preservatives found in shampoos, conditioners, make-up products, lotions, moisturisers and even sunscreens can cause a skin rash allergy².

• Certain metals. These typically include nickel or cobalt in jewellery¹³.

Symptoms of an allergic skin rash

Symptoms of a skin rash allergy can range from mild to severe². They can develop in one area or all over the body. Common symptoms of a skin allergy can include skin that is¹⁴:

• Itchy

• Inflamed or swollen

• Red in colour on pale skin or purple/brown on dark skin⁶

• Painful to the touch

• Scaling or flaky

• Stinging or burning

• Blistering

• Dry or blotchy

How to manage an allergy rash

You can get in touch with your GP to have your skin allergy rash tested. This can help you identify the cause of your allergy. Tests that your GP may give you include a skin prick or patch test to see if your skin reacts. They may also conduct a blood test to check for allergens¹.

Treatments for skin rash allergies can include:

• Avoiding triggers. Avoid any of the things that you’re allergic to where possible¹.

• Taking medication. This may include antihistamines or steroid creams (topical corticosteroids), depending on the type of skin allergy that you have¹.

• Applying a cool compress or taking a cool shower. A cool shower or cool compress can help calm a stinging or burning skin allergy rash. After the shower, gently dry the skin and moisturise¹⁵.

If your symptoms are not severe, you can manage your skin rash allergy by using BENADRYL® allergy relief products. You can also find ways to effective management techniques with our in-depth guide to managing your allergy.