Heat Rash vs Hives: What’s the Difference?

Both heat rash and hives can cause red bumps, rashes, and itching, which often makes them hard to tell apart.

However, these skin problems have different causes and treatments.

Let’s get to know the differences so you can manage them properly.

What Is Heat Rash?

Heat rash (miliaria) occurs when sweat gets trapped under the skin due to blocked pores.

This condition often happens in hot and humid weather, after intense physical activity, or when lying in bed for too long.

Other triggers that increase body temperature, such as using medicated patches, can also cause it.

Common symptoms of heat rash include:

• Small red or clear bumps on the skin
• Itching, stinging, or prickling sensation
• Usually appears on skin folds such as the armpits, neck, back, chest, inner elbows, or groin

Heat rash isn’t dangerous and usually improves by keeping the skin cool and dry.

However, if left untreated, it can cause irritation or secondary infection due to excessive scratching.

What Is Hives?

Hives (urticaria) are an allergic skin reaction characterized by red or white, itchy, and sometimes painful bumps.

They can vary in size and may spread to other parts of the body.

In some cases, the bumps merge into larger patches (plaques) and usually fade within 24 hours, though they can last longer in certain cases.

Common triggers include:

• High-protein foods such as eggs, shrimp, or seafood
• Cold exposure or sudden temperature changes
• Insect bites
• Certain medications, like antibiotics or anti-inflammatory drugs
• Stress or autoimmune conditions

Treatment and Prevention: Heat Rash vs Hives

Although both cause itching and discomfort, the treatment differs since the underlying causes are not the same.

Here’s how to treat and prevent each condition effectively.

How to Treat Heat Rash

The main goal is to keep the skin cool and dry to prevent further irritation.

Steps you can take at home:

1. Keep the skin cool and dry

• Wear loose, cotton clothing that absorbs sweat easily.
• Use light bed sheets.
• Take cool showers to soothe the skin and relieve itching.
• Stay hydrated to lower body temperature and prevent dehydration.

2. Soothe itching and irritation

• Apply a cool compress for 10–20 minutes using a damp cloth.
• Avoid scratching; gently pat the area instead.
• Avoid fragranced soaps or creams that can worsen irritation.

How to Treat Hives

Most cases of hives go away within 24 hours, but you can relieve symptoms and prevent recurrence with these steps:

1. Take antihistamines

• These help reduce itching and swelling caused by allergic reactions.
• Available in oral or topical (cream) form.

2. Home remedies

• Take a cool shower to calm the skin.
• Wear loose, soft clothing to let your skin breathe.
• Apply a cold compress to itchy areas.
• Use hydrocortisone or topical antihistamine creams to reduce discomfort.

3. See a doctor if symptoms are severe

    If antihistamines are not effective, your doctor may prescribe:

• Oral steroids (e.g., prednisone) for severe inflammation.
• Epinephrine (adrenaline) for acute allergic reactions (anaphylaxis) — symptoms include facial swelling, shortness of breath, and a sudden drop in blood pressure. This requires immediate emergency care.

How to Prevent Heat Rash and Hives

To keep your skin healthy and avoid flare-ups:

• Avoid excessive heat and humid environments.
• Use sunscreen to protect your skin from UV irritation.
• Stay away from foods or allergens that previously triggered hives.
• Keep your skin and clothes clean.
• Choose gentle, non-comedogenic skincare products to prevent clogged pores.

To support skin regeneration and minimize the risk of scars or dark spots after heat rash heals, you can use wund+™ Scar Gel containing centella reversa stem cells.

Its formula helps accelerate skin repair and keeps the skin smooth after irritation.

References

Center for Dermatology and Laser Surgery. Accessed in 2025. Rash or Allergic Reaction?: How to Tell the Difference.

Healthline. Accessed in 2025. Cholinergic Urticaria: Can Heat Cause Hives?

OSF Healthcare. Accessed in 2025. Heat rash, sun rash — what’s the difference?

NHS UK. Accessed in 2025. Heat rash (prickly heat)