For many Australians, summer means outdoor activities. Many people get sunburn during the summer months and sun safety is important for all of us. But aside from sunburn, some people may get other rashes.

These rashes can be caused by things like sunlight, insects, sweating and overheating during the summer months — especially if they have allergies and/or pre-existing skin conditions. Babies are especially susceptible to skin rashes because their skin is often more sensitive.

There are several different types of skin rashes; here are some that can occur during the summer months.

Heat rash or prickly heat

Heat rash or prickly heat is a harmless but very itchy skin rash forming small red spots in places where sweat collects, such as the armpits, back, under the breasts, chest, neck, groin, crooks of elbows and knees, and the waist.

Heat rash is caused by a blockage and inflammation of sweat ducts in heat and high humidity, which causes:

• tiny red spots
• an irritating itch and prickling sensation
• redness and mild swelling of the affected area

Read more about how to cope in hot weather.

Sun rash

Some people have skin that can develop rashes with exposure to direct sunlight, including people on certain antibiotics, or people exposed to some chemicals, fragrances, dyes, or disinfectants. This is called photodermatitis.

In some people, exposure to the sun in the spring or early summer can trigger an itchy, red rash on the front of the neck, chest and the arms and thighs called polymorphous light eruption (PMLE). It usually clears without treatment in a few days, although it can come back.

Sunlight can also trigger a rare condition called lupus (systemic lupus erythematosus or SLE) in susceptible people.

Read more about sun safety.

Skin allergies

Spring and summer are times when there are many substances that can cause allergic skin reactions in the environment — moulds, pollens, plant and animal substances.

• hives (urticaria) can be triggered by heat or sweat
• eczema (atopic dermatitis) can worsen in the summer, especially with excess sweating
• certain plants and grasses can cause skin rashes

Rashes from bites and stings

Bites and stings usually cause pain and slight swelling, but they can cause a severe skin reaction in some people, particularly if they are allergic to stings. Sometimes the reaction is localised to swelling at the site of the bite or sting. This may be many centimetres wide but gradually goes away over a few days.

In some people the reaction to the bite or sting affects their whole body and can cause itchy skin anywhere on the body, swelling of the face, lips, tongue, throat, and upper airway, a fast heart rate and low blood pressure.

A severe allergic reaction affecting the whole body is called anaphylaxis and is a medical emergency.

Read more about bites and stings.

Chronic skin conditions

Many people with chronic skin conditions may find their symptoms worsen during summer. You should see your doctor if you have an ongoing skin problem that is worsened by heat and sunlight. People with these conditions may need to take special precautions. Examples of chronic skin conditions include:

• chronic fungal infections such as tinea
• atopic dermatitis (eczema)
• seborrhoeic dermatitis
• skin cancers and pre cancers (called actinic or solar keratoses)

Self-care and treatments

Most summer skin rashes are not harmful and will disappear by themselves after a few days. Most rashes can be safely and effectively treated at home. Try one or more of these measures:

• Wear light, loose-fitting soft clothes that don’t trap heat and moisture. Natural fabrics such as cotton are best.
• Spend time in cool, air-conditioned or well-ventilated environments. Use a fan if necessary.
• Take frequent cool baths or showers.
• Ask your doctor or pharmacist if there are any creams or tablets that may help you.
• Don’t scratch the affected area, as it may worsen and become infected.

It’s also important to drink plenty of water in hot weather and ensure you reduce sun exposure to your skin.

When to seek medical help

See your doctor if the rash doesn't improve by itself, seems to be getting worse or if you have signs of skin infection such as:

• pain, swelling, redness or warmth around the affected area
• pus draining from the lesions
• swollen lymph nodes in the armpit, neck or groin
• a fever or chills

Rarely, some rashes are an early stage of serious infections affecting the whole body, the brain or spinal cord.  You should see your doctor or call triple zero (000) if your rash is associated with:

• severe headache, neck stiffness, and fever
• vomiting and nausea

In an emergency

Anaphylaxis

It is normal for bee and wasp stings to cause a minor rash. However, in some people with allergies, stings can cause a severe reaction called anaphylaxis. Anaphylaxis is a medical emergency.
 Call triple zero (000) for an ambulance if you (or a person you are with) get symptoms such as dizziness, difficulty breathing, swelling or tightness in the throat or a rapid pulse.

If the person has a 'personal action plan' to manage a known severe allergy, they may need assistance to follow their plan. This may include administering adrenaline to the person via an autoinjector (such as an Epipen®) if one is available. The Australasian Society of Clinical Immunology and Allergy recommends that for a severe allergic reaction adrenaline is the initial treatment. For further information, visit the Choosing Wisely Australia website.

The St John Ambulance Australia first aid fact sheet for anaphylaxis can be found on their website.

Learn about setting up a personal action plan for someone affected by anaphylaxis.

You can read more about anaphylaxis in the bites and stings section.

Heat stroke and heat exhaustion

Heat rash may also be an early warning of heat stroke and heat exhaustion.

Call triple zero (000) immediately if you (or a person you are with) get symptoms of heat stroke such as a sudden rise in body temperature, red, hot dry skin (because sweating has stopped), dry swollen tongue, rapid pulse, rapid shallow breathing, intense thirst, headache, nausea and vomiting, dizziness, confusion, poor coordination or slurred speech, aggressive or bizarre behaviour, loss of consciousness, seizures or coma.

More information

There are a number of resources and services available if you need help or more information on summer rashes:

• your doctor, pharmacist or the emergency department of your nearest hospital
• the Poisons Information Centre telephone advice line on 13 11 26 (24 hours a day, 7 days a week)
• healthdirect on 1800 022 222 (known as NURSE-ON-CALL in Victoria) to talk to a registered nurse (24 hours a day, 7 days a week)