Skin Rash Vs Hives

Overview

When your skin suddenly flares up with red patches (on lighter skin) or light to dark brown, purple or grey patches (on darker skin) that are itchy and uncomfortable, it can be worrying. But are you dealing with hives or a different type of skin rash? Understanding the difference between rashes is important, as each condition has its unique causes, symptoms, and treatments. This article dives into how to differentiate between hives and other skin rashes so that you are better equipped to recognise, treat, and prevent these conditions.

A skin rash is a term used to describe any obvious change in the texture or colour of the skin, often accompanied by redness or light to dark brown, purple or grey patches, itching, or irritation. A simple rash is called dermatitis, meaning inflammation of the skin. They can appear anywhere on the body and vary widely in appearance and cause. Hives are a specific type of rash that has a smooth raised appearance. Unlike most rashes, hives often develop quickly and may disappear just as quickly, normally as a result of an allergic reaction.

It is important to be able to differentiate between hives and other types of skin rashes because each condition has different causes and requires different approaches to treatment therefore, knowing these differences, can help with promptly addressing the underlying issue and choosing the appropriate treatment to provide relief from symptoms.

Causes

Common causes of a rash include:²

• Eczema (atopic dermatitis) which results in a rash that is generally red or purple, grey, or white patches, itchy, and scaly
• Psoriasis which occurs as red or purple, grey, or white patches, scaly, patches over joints and along the scalp
• Impetigo which is an infection from bacteria that live in the top layers of the skin, commonly affecting children. It appears as red or purple, grey, or white sores that turn into blisters, ooze, then form a honey-coloured crust over all or part of the rash

Some of the causes for hives can also be the cause of other skin rashes. Allergies are a frequent culprit for hives. When your body reacts to an otherwise harmless substance, such as dust, pollen, or animal fur, it is called an allergy. Although the symptoms may not be severe for some, they can be for others. It can result in a raised rash (hives) but also result in a skin rash that is red (on lighter skin tones) purple, grey, or white (on darker skin tones) and itchy.³

Infections can also cause hives in addition to other skin rashes, whether bacterial, viral, or fungal and can lead to rashes that you may see in conditions such as impetigo, chickenpox, or ringworm.¹

Despite these shared causes, hives may be more susceptible to physical triggers such as pressure, temperature changes, sunlight, or exercise compared to other skin rashes. However, unlike a simple rash, hives tend to appear more suddenly and can spread across the skin, although, often resolve within hours to days. Hives can also be brought on by emotional or physical stress.¹

Symptoms

Hives are more distinct in their presentation compared to simple skin rashes. Typically, hives can¹

• Look like raised bumps or patches in many shapes and sizes
• Appear anywhere on the body 
• Be on 1 area or spread across the body to feel itchy, sting or burn
• Change shape or move around the body within a short period
• Look pink or red when affecting someone with white skin although the colour of the rash can be harder to see on brown and black skin and may appear similar in colour to their skin tone

Skin rashes can present a variety of symptoms which depend on their cause. The most common symptoms include a change in the colour of the skin, where it turns visibly red or inflamed on lighter skin or may appear purple, grey, or white on darker skin. In addition to this, patients may have itchy skin which may cause discomfort and a strong urge to scratch. It is, however, important to not scratch as doing so can worsen the condition. Sometimes rashes can lead to blistering, where small fluid-filled bumps appear on the skin that may burst and crust over. Scaling is also another symptom which involves dry, flaky patches of skin that may peel or shed.

Treatments

The treatments for hives can be very similar to the treatments for other skin rashes. To be able to determine the correct treatment, you must first find the root cause of the rash. For conditions such as eczema (atopic dermatitis), psoriasis or impetigo (if it is concentrated in 1 area), creams may be the first line of treatment, depending on the cause of your rash. For hives, a GP may prescribe menthol cream.¹

However, if the hives or other skin rash is caused by allergies, antihistamines may be used as treatment as it helps to reduce the itching and swelling which comes from an allergic reaction. If it is caused by an infection or autoimmune disease, on the other hand, antibiotics, antivirals or immunosuppressive drugs can be used to treat it. It is also important to try to avoid known irritants or allergens that trigger the hives or other skin rash to prevent episodes and recurrence.¹

Conclusion

In conclusion, distinguishing between different skin rashes and hives is important for effective treatment and management. Although very similar, different rashes can present very differently and can have many different causes and understanding these differences allows for prompt and appropriate care, whether that means using topical creams for rashes like eczema or psoriasis, or antihistamines to manage hives caused by allergic reactions. By recognising the presentations of different rashes, patients can have a better understanding of how to prevent and alleviate symptoms.

FAQs

How can I tell if my skin condition is hives or another rash?

Hives present as raised smooth skin that can vary in size and may move around the body. Hives often develop suddenly and may disappear within hours, whilst other rashes may persist for longer periods. Other rashes will also present differently depending on their cause.

Should I see a doctor if I develop hives or a rash?

Typically, hive rashes get better within a few days and you can often treat hives yourself. However (according to the NHS), please contact your doctor if:¹

• symptoms of hives do not improve after 2 days
• you're worried about your child's hives
• the rash is spreading
• hives keep coming back (you may be allergic to something)
• you also have a high temperature and feel unwell

If you believe that you have another rash that is not hives, it is also important to contact your doctor if it is persistent, or accompanied by other symptoms like difficulty breathing, fever, or swelling.

How can I prevent future episodes of hives or rashes?

You cannot always prevent hives. You get hives when something causes high levels of histamine and other chemicals to be released in your skin. This is known as a trigger. Preventing hives involves identifying and avoiding known triggers, such as specific allergens, irritants, or stressors. By avoiding these triggers, you may be able to avoid an episode of hives. This principle may also be applied to other rashes unless your rash is caused by an infection or autoimmune disease.

Are hives contagious?

Hives are not contagious. They are normally caused by allergic reactions, stress, or physical triggers, none of which can be passed from person to person. However, if hives are triggered by an infection, that condition itself might be contagious.⁴

Can hives or other rashes leave scars or cause long-term skin damage?

Hives normally do not leave scars or cause long-term skin damage, as they usually resolve within a day, without lasting effects. However, other rashes that are severe or not treated properly, particularly those that involve blistering, scratching, or infection, may lead to scarring or hyperpigmentation, especially on darker skin tones.