Skin Allergies: Symptoms, Causes, and Treatment

Skin allergy types

There are three common types of skin allergies³ and each one has slightly different symptoms or triggers.

Hives (Urticaria)

Hives, or urticaria, are raised, itchy red welts or bumps that appear on the skin². They’re often triggered by²:

• Contact dermatitis

• Insect bites

• Medication allergies

• Foods allergies.

Hives tend to appear immediately after you’ve come into contact with an allergen and should start to fade in a few hours or days, depending on the severity of your allergy and how quickly you remove the trigger².

Hives are usually split into two types.

Acute hives

Acute urticaria can occur upon eating specific food or coming into contact with a trigger. It can also result from other factors, such as heat, exercise, medication reactions, or insects.

Chronic hives

Chronic hives/urticaria is an ongoing reaction that many different triggers could cause. It can last for years.

Contact dermatitis

Contact dermatitis is a type of eczema triggered by contact with a particular substance or allergen⁴. If you’ve ever got a rash after wearing a new ring, using a different soap or changing your laundry detergent, you may have had this condition⁴.

Certain airborne allergens, such as pollen, can also trigger dermatitis when they come into contact with your skin². This is known as “airborne contact dermatitis².”

Some people find they only have a reaction after being in the sun². This is known as “photoallergic contact dermatitis².” It’s caused by certain chemicals commonly found in sunscreens, shaving lotion, and perfumes².

Eczema

Eczema, or atopic dermatitis, is a chronic condition that usually starts in childhood⁵. The word ‘atopic’ means a sensitivity to allergens, meaning that certain triggers can cause your skin to become itchy, dry, flaky, and red⁵. While experts aren’t sure what the exact cause of eczema is, common triggers typically include:

• Pet dander²

• Dust²

• Stress⁵

• Detergents and soaps⁵

• Certain cleaning products.²

Skin allergy symptoms

Hives symptoms

Hives develop as a raised, itchy rash made of bumps or welts in many shapes and sizes². Some people get hives all over their body, but many only develop a rash on small patches of skin⁶. They’re also common in both adults and children⁶. An itching sensation usually identifies the rash, but it may also feel like stinging or burning⁶.

A hives rash typically looks red against white and pale skin. But the colour is often harder to see on brown, black and darker skin tones⁶.

A breakout of hives should settle down within a few minutes to a few days⁶.

Contact dermatitis symptoms

Contact dermatitis symptoms are usually caused by an irritant that touches your skin⁴. In these cases, symptoms typically appear within 48 hours or, in some cases, immediately⁷. Some milder irritants (such as soap and detergents) may only cause symptoms after frequent exposure⁷.

Occasionally, the patches of skin affected by contact dermatitis can become infected⁷. You can spot an infection from the following signs⁷:

• Your existing symptoms worsen

• Discharge from your affected skin

• Increasing pain levels

• Feeling generally unwell, hot, or shivery.

Atopic eczema symptoms

Atopic eczema is a skin allergy that causes itchiness, and dry, cracked, and sore skin5. Some people only experience eczema as small patches of dry skin, but others get larger areas of inflamed skin all over the body5. Some of the more common areas affected by eczema include⁵:

• Hands

• Insides of elbows

• Backs of knees

• Face

• Scalp (especially common in children).

Inflammation caused by eczema often looks red on lighter skin. It can be harder to spot on darker skin but usually comes up in a darker brown, purple, or grey colour⁵.

Skin allergy and hives causes

Skin allergies occur when your immune system reacts to a particular substance (an allergen) as though it's harmful¹. It causes the release of antibodies, which results in many of the allergy symptoms we recognise – including hives². It's unclear why some people react to specific allergens or triggers, but most people affected tend to have a family history of allergies or other closely related conditions, like asthma¹.

Triggers can include:

• Eating certain foods – particularly shellfish, fruit, nuts, eggs, or cow’s milk¹

• Skin contact with certain plants, animals, chemicals, and latex¹

• Cold, dry weather⁸

• Medications, such as antibiotics or non-steroidal anti-inflammatory drugs (NSAIDs)⁹

• Insect bites or stings¹

• Pressure on your skin¹⁰

• Hard or heavily chlorinated water¹¹

• Stress⁸

• Sweaty skin⁸

• Metals in jewellery (specifically nickel and cobalt)¹²

• Adhesives, such as the sticky substances in plasters¹²

• Scents or fragrances found in cosmetics such as perfumes, soaps, and lipsticks¹²

• Essential oils.¹²

Diagnosis of skin allergies

If you suspect you may have a skin allergy, you should speak to your GP¹³. They will use one or more of the following diagnostic techniques to determine whether you have a skin allergy, what might be triggering it, what type of allergy you have, and how best to treat it

Diagnosis methods for skin allergies can include:

Blood tests¹³

Either used alongside or instead of skin prick tests, blood tests can help diagnose a range of common allergies. Your doctor will take a sample of your blood and analyse the specific antibodies produced by your immune system in response to certain allergens.

Patch tests¹³

Patch tests are a common way of diagnosing contact dermatitis. They expose your skin to a specific allergen by adding a small amount of the allergen to a metal disk and then securing it to your skin for 48 hours. Your doctor will then monitor your skin for a reaction to determine whether you’re affected by it or not.

Elimination diet¹³

Elimination diets are a useful way of diagnosing potential food allergies. They involve reducing or removing particular foods from your diet for a few weeks, before reintroducing it and monitoring the effects this has on your body. If you notice your symptoms ease up when you remove the food from your diet and flare up again when you reintroduce it, it’s likely you have an allergy. You should only ever attempt an elimination diet with the support of a qualified healthcare professional.

Challenge testing¹³

Another way of diagnosing food allergies is challenge testing. During these tests, you’ll eat the food you think you’re allergic to. You’ll be asked to gradually increase the amounts you eat to see how your body reacts. Challenge testing is often thought to be the most accurate form of food allergy diagnosis but should only be carried out in a clinic under medical supervision in case you have a severe reaction.

Allergy testing kits¹³

Most at-home allergy kits have a lower standard than those provided by the NHS or approved clinics and so may not be completely reliable. Ideally, your allergy tests should be monitored and interpreted by your GP or another healthcare professional with knowledge of your medical history and symptoms.

Skin allergies and hives treatment

If you have a flare-up of a skin allergy or hives rash, there are several things you can do to try and manage it until your symptoms subside. Here are a few of our top tips for managing your skin allergy:

Avoid allergens

If you can identify the cause of your skin allergy, your best chance of reducing symptoms is to avoid the trigger all together or limit your exposure if complete avoidance isn’t possible²

Apply natural treatment

Ground down oatmeal powder mixed with water can be a good natural remedy for some people. Always mix with warm (not hot) water.

Let it breathe

Don’t wear tight clothes as these can rub and irritate your rash. Instead wear loose-fitting clothing that gives your skin space.

If you are still suffering, you may require medication. There are various allergy treatment options available, including:

Antihistamines

Emollients

Emollients are a form of moisturising treatment that help soothe dry or scaly skin¹⁵. They’re commonly used to help treat skin allergies like eczema and contact dermatitis¹⁵. Emollients come in several different forms, and it may take some trial and error before you find one that works best for you¹⁵.

You should apply a generous amount of your chosen emollient to the affected patch of skin and gently rub it in until it’s absorbed¹⁵. Make sure you smooth the emollient out in the same direction as your hair growth to avoid irritating the skin further¹⁵.

Immunotherapy

If you have a severe skin allergy, your GP may suggest immunotherapy¹⁶. This is where you’re exposed to occasional small doses of an allergen over the course of several years¹⁶. This won’t cure an allergy but can help your body become more tolerant of the allergen, so that it’s less likely to have a severe reaction to it in the future¹⁶.

Topical corticosteroids

If your skin allergy has caused your skin to become sore and inflamed, your GP may suggest using a topical corticosteroid as part of your treatment¹⁵. These can help quickly reduce the inflammation caused by your allergic reaction¹⁵. Like emollients, topical corticosteroids should be applied directly to the affected area of skin¹⁵.

Steroid tablets

If your contact dermatitis covers large areas of your body or you have hives all over your body, a topical treatment may not be suitable or practical^{15 16}. In these instances, you might be prescribed steroid tablets to take orally^{15 16}. The tablets will act in a similar way to other treatments, by helping to reduce the inflammation of your skin allergy¹⁶.

Phototherapy

In some cases, your GP may suggest phototherapy. This involves exposing the affected patch of skin to ultraviolet (UV) light with the intention of improving its appearance and reducing your rash¹⁵.

When to see a GP about your skin allergy

You should consult a GP about your skin allergy if:

• The symptoms do not improve after two days of using at-home and OTC treatments⁶.

• You’re worried about your hives on your child⁶.

• The rash is spreading to more areas of the body⁶.

• You have chronic hives (hives that keep coming back)⁶.

• Your skin allergy is accompanied by high temperature and feeling generally unwell⁶.

• You notice swelling under the skin – this might be a sign of angioedema⁶.

• You have blue skin around lips – this could be a sign of anaphylaxis, which is a medical emergency that requires immediate treatment¹⁷.