What are summer skin rashes?

Summer skin rashes are rashes that often start, or get worse, in hot or humid weather or after being in the sun.

They may form red, itchy, scaly patches, bumps or blisters on parts of your skin exposed to the sun.

Babies are more likely to get skin rashes. This is because their skin is thinner, has little or no hair and makes less sweat and oil.

What causes summer skin rashes?

Summer skin rashes happen when things like sunlight, heat or allergens irritate your skin or trigger your immune system to react.

Common causes include:

• exposure to sunlight (ultraviolet radiation)
• hot or humid weather
• sweating a lot or wearing tight, heavy clothes that trap heat and moisture
• medicines that make your skin more sensitive to sunlight
• reactions to plant allergens (tiny particles from plants, trees, grasses or weeds)
• insect bites and stings
• sunburn

Common skin problems that can cause summer skin rashes include:

• heat rash (miliaria)
• different types of dermatitis — such as summer-associated dermatitis, photoallergic contact dermatitis and sweat dermatitis
• skin conditions that make you sensitive to sunlight — such as polymorphous light eruption (PMLE)

Some skin conditions may get worse during summer. Skin allergies can also get worse at this time.

When should I see my doctor?

See your doctor if:

• the rash doesn’t improve after a few days in a cool place
• the rash covers a large area
• the rash keeps coming back
• you have signs of skin infection such as redness, warmth, pus or fever
• you are worried about your rash

When to seek urgent care

Seek urgent care if you have a severe allergic reaction (anaphylaxis) to bites and stings. This is a medical emergency. Symptoms may include:

• difficulty breathing
• swelling of the lips, tongue, face and throat
• dizziness or fainting
• nausea and vomiting

If you think you or someone you know is experiencing anaphylaxis, use the adrenaline autoinjector immediately. Then call triple zero (000) and ask for an ambulance. Follow an ASCIA allergy action plan, if you have one.

Follow instructions on how to use an adrenaline autoinjector, if required. ASCIA allergy action plans are available for people with various allergies.

Sometimes a rash is a sign of heat-related illness. Heatstroke is the most serious form, when your body overheats and can no longer keep a healthy temperature. Other symptoms may include:

• feeling unwell
• headache
• nausea
• confusion or unusual behaviour (delirium)
• loss of consciousness (coma)

Heatstroke is a medical emergency. Call triple zero (000) and ask for an ambulance if someone has symptoms.

How are summer skin rashes treated?

Treatment for summer skin rashes depends on the cause.

Self-care at home

You may be able to treat some summer skin rashes at home. Try one or more of these measures:

• Stay in a cool, ventilated place.
• Take cool baths or showers to wash off sweat and bacteria.
• Wear loose cotton clothing and avoid tight or synthetic fabrics.
• Use a gentle moisturiser.

Read more about sun safety and what to do in hot weather.

Medicines for summer skin rashes

The best medicine to use for a skin rash depends on the cause. Options may include antihistamines or corticosteroid creams.

Ask your doctor or pharmacist which creams or tablets might help.

If your rash is a side effect of another medicine, talk to your doctor or pharmacist about your options for other treatments.

What are the complications of summer skin rashes?

Some rashes may lead to scarring.

Heat rash spots can sometimes get infected and form lumps filled with pus. If the rash covers a large part of the body, it can also cause a fever and make you feel sick from the heat.

Can summer skin rashes be prevented?

You can help prevent some summer skin rashes by:

• staying out of the sun if it triggers your rash
• keeping away from plants you are allergic to
• protecting yourself from insect bites or stings by using repellent

To prevent heatstroke, drink plenty of water in hot weather and try to stay in the shade or air conditioning. Read more on managing heatstroke.

Resources and support

For more resources on poisons, anaphylaxis and allergies:

• Call the Poisons Information Centre telephone advice line on 13 11 26.
• The St John Ambulance Australia offers a first aid fact sheet for severe allergic reactions.
• Australasian Society of Clinical Immunology and Allergy (ASCIA) has information on setting up a personal action plan for someone with anaphylaxis.

For more resources on heat-related illnesses:

• DermNet has information about heat rash.
• NSW Health has fact sheets on heat-related illness and tips to beat the heat.

For more information on hot weather safety:

• The Royal Women’s Hospital has information on heatwave precautions for babies and young children.
• Australian Red Cross has information on the risks and potential impacts of extreme heat in your area.
• Queensland Government has information on hot weather, health and safety.
• The Northern Territory Government has a video on heat safety.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

Languages other than English

NSW Health has translated resources on protecting yourself from the heat.

Information for Aboriginal and/or Torres Strait Islander peoples

Aboriginal Community Controlled Health Organisations (ACCHOs) offer culturally tailored advice on heat safety and general health.