Hives vs Eczema: Know the Difference
Hives vs eczema: how are they different? Well, they are two major types of allergic skin conditions that affect both children and adults alike. They both manifest as a rash, cause intense itching and have known triggers. However, they are not the same and must not be confused with each other.
What Is Eczema?
Eczema is a common inflammatory skin disorder that is often associated with asthma, allergic rhinitis and food allergies. It goes by many names, including atopic eczema or atopic dermatitis, and is commonly described as an “itchy red rash in the skin folds”.
In about 70% of cases, eczema starts within the first six months of life and may persist for several years. By age 15, up to 75% of those affected will have gone into remission. However, some of them may remain vulnerable to flares and dry skin. Eczema recurs in some adults, particularly on the hands. Adults with eczema usually have a chronic type and more severe symptoms.
What Are Hives?
A person with urticaria often develops a form of rash called hives and/or angioedema (swelling of the area beneath the skin). Hives usually appear on the skin as a cluster of pale red bumps or a slightly elevated swelling (wheal). Hives can also occur when a person experiences a severe allergic reaction known as anaphylaxis.
While eczema is an ongoing condition that tends to flare periodically, hives typically last for a few minutes, or several hours to days. This is a major distinction for hives vs eczema. In some cases, hives can last for more than six weeks and recur frequently. This type is called chronic urticaria. Urticaria is often confused with a variety of skin conditions that are similar in appearance and are associated with itching, but an experienced clinician can distinguish the difference between these diseases.
Causes of Eczema
The exact cause of eczema is unclear. It appears to run in families and may also be triggered by stress and environmental factors. Physical and chemical irritants, allergens and infections can worsen eczema. Additionally, people suffering from eczema have a dysfunctional skin barrier which leads to various skin problems:
- Water escapes easily from the skin leading to dry, dehydrated skin
- The skin is more susceptible to infection
- Harmful substances can easily penetrate the skin, causing irritation
Research shows that the dysfunctional skin barrier in eczema patients has a genetic component. People with a mutation in a gene called filaggrin (the gene that creates the tough, flat cells that form the outermost protective layer of the skin) will have a “leaky” skin barrier due to the haphazard organization of these cells.
Causes of Hives
Urticaria occurs when the skin comes in contact with an allergen or an allergen enters the body (via food or air breathed in). The allergen then activates the immune cells called mast cells to release histamine. Histamine is a protein responsible for itching and the formation of hives. Histamine also causes blood fluids and cells to leak from blood vessels into the surrounding tissue, resulting in wheals.
In contrast, the itch in eczema is not linked to histamine. That is why anti-itch drugs (antihistamine) that are used to relieve hives do not work for eczema.
Some known eczema triggers may also trigger urticaria:
- Pet dander
- Certain food
- Changes in temperature
Symptoms of Eczema
To many people, eczema and atopic dermatitis mean the same thing, but the latter is actually a type of eczema. If you have one type of eczema, you may also develop other types depending on your genes and exposure to triggers.
The common symptom in all types of eczema is red, itchy, inflamed skin, but there are other important features to consider:
- Early age of onset
- Personal or family history of asthma or hay fever
- The appearance of bumps or papules
- Increase or decrease pigmentation in the skin after eczema clears
- Dry, scaly skin resembling fish scales
- Skin thickening (lichenification)
Symptoms of Hives
Hives can show up anywhere on your body. More than one type can coexist in one person.
Signs and symptoms to look out for:
- Itching or burning sensation
- Central swelling of variable size (wheal)
- Redness of the surrounding skin
- The center of the hives turns pale when pressed (blanching)
- Skin returns to its normal appearance within 24 hours
- Wheals may reappear or move to another body part
- Wheals may join together and cover large areas of the body (plaques)
Treatment for Eczema
The best way to manage eczema is to identify and avoid triggers. Reducing the itch is the primary goal of treatment. As mentioned above, antihistamines do not relieve the itch in eczema unless it has an urticarial component.
Topical corticosteroids and other anti-inflammatory creams are used to treat an eczema rash. A good skincare regimen for atopic dermatitis involves moisturizing creams or lipid-replenishing products generously applied to the skin at least twice a day to combat dry skin.
Treatment for Hives
Like eczema, the treatment for urticaria is to avoid potential triggers. However, the cause for most patients with chronic urticaria cannot be determined. Antihistamines are often prescribed for acute and chronic cases.
Oral corticosteroids and biologics are prescribed for patients who do not respond to initial treatment. You may apply a cool compress to the affected area while waiting for your medication to take effect.