Updated 11 February 2013


A rash involves changes in the colour or texture of the skin. In most cases the cause of the rash can be determined by its visible characteristics or other symptoms.


  • A rash involves changes in the colour or texture of the skin
  • In most cases the cause of the rash can be determined by its visible characteristics or other symptoms
  • Treatment will depend on the cause of the rash

Alternative names

Skin redness or inflammation, skin lesion, rubor, skin rash, erythema

What is a rash?

A rash is a superficial eruption of the skin, consisting of small spots, bumps or blisters, redness (erythema) or scaliness.

What causes it?

Common causes include:

  • Rashes in infancy - acommon infant rash is the nappy rash, caused by long periods of skin contact with damp nappies, bacteria and the baby's waste. Three weeks after birth babies may develop 'acne' caused by the mother's hormones before birth. "Seborrhoeic dermatitis" is a rash often seen in otherwise healthy infants in the first six months. It consists of non-itchy scaly red patches, often most marked in the nappy area, and yellow scaly crusts on the scalp.
  • Infectious illness - a common symptom of many childhood illnesses is a rash - examples are chicken pox and scarlet fever. Other childhood illnesses that cause a rash are: measles, German measles (rubella), impetigo, roseola, Kawasaki disease, hand-foot-mouth disease and "slapped cheek disease" ( erythema infectiosum).
  • Atopic dermatitis - thisis the most common form of eczema. It is a hereditary skin problem that often starts in infancy with intensely itchy dry, chapped, bumpy areas on the cheeks and body, eventually focusing on the skin folds around the elbows and knees. Severe cases of eczema may cause red, scaly and swollen skin over the body.
  • Allergic reactions - t here are also other ways in which allergy affects the skin. One of them is anitchy rash known as urticaria. Contact dermatitis is a rash caused by contact with an allergen such as metal, rubber and poison plants. An allergic reaction to a drug is another common cause of rash. A drug allergy rash may start within two weeks of starting new medication.
  • Autoimmune disorders - these are conditions in which the immune system turns on the body such as systemic lupus erythematosus . They often have a distinctive rash.
  • Other - rashes may also be caused by a number of fungal and bacterial infections. Impetigo is a blistery or crusted rash due to certain bacteria. Purpura means bleeding spots in the skin, and this is a symptom which should never be neglected , as there are several serious causes. Lastly, a common cause of rashes is the bites of fleas or mosquitoes, to which one may become allergic. And scabies is a troublesome itchy rash due to a parasite (the scabies mite) burrowing in the skin.

Home care

Good skin care can help the healing process, ease discomfort and prevent secondary scars and infection.

  • Use a mild soap or water to wash the affected area
  • Take showers and quick baths and use warm not hot water
  • Don't scrub your skin
  • When drying your skin you should pat your skin gently as rubbing will remove natural oils
  • Keep your skin moisturised
  • Wear natural fibres such as cotton which allows skin to circulate over affected areas
  • To relieve itchy or sore areas apply a cool or lukewarm compress
  • Avoid exposure to irritants

How is it diagnosed?

The doctor will do a physical examination and will ask you questions about your medical history to try to find the cause of the rash.

Your doctor may ask the following questions:

  • When did the rash begin?
  • What parts of the body are affected?
  • Does anything make the rash better or worse?
  • Have you used any new soaps, detergents, cosmetics or lotions recently?
  • Have you been in any wooded areas recently?
  • Have you had any change in your medications?
  • Have you noticed a tick or insect bite?
  • Have you noticed anything unusual lately?
  • Do you have symptoms like itching or scaling?
  • Do you have any underlying medical conditions such as allergies or asthma?

How is it treated?

Soothing lotions, oral antihistamines and topical antibiotics can provide relief.

If the rash is triggered by an allergen the rash will clear up once the allergen is removed. Drug allergy rashes will fade once the person stops taking the medication.

For eczema, treatment will include topical steroids, over-the-counter and prescription creams. The doctor may also prescribe emollient which retain the water in the skin and keeps it soft and smooth as well as soothes.

Fungal infections can be treated with antifungal creams that can be bought without a prescription such as Lamisil.

Antibacterial creams are not very effective for bacterial infections and should rather be treated with oral antibiotics and prescription creams.

To treat nappy rash the baby's skin should be exposed to as much air as possible. Ointments will only be needed if the skin is cracked. It is also recommended that you switch to cloth nappies and clean the affected area with water.

When to call your doctor

Call your doctor if you experience any new symptoms, if the rash gets worse and if it does not respond to treatment.


Rashes caused by infection or an allergic reaction will disappear once the infection or irritation leaves the body's system.

Rashes caused by a chronic condition such as systemic lupus erthematosus may remain, fade and return constantly.


The best line of defence is to keep your skin healthy, be gentle with your skin, eat a healthy diet and exercise.

Keep these tips in mind:

  • Always protect your skin from the sun, wear sunscreen
  • Identify and stay away from plants and products that irritate your skin.
  • If you have eczema, do not use harsh soaps that may dry out your skin
  • Wash your hands regularly to avoid spreading viruses
  • Make sure you are vaccinated against childhood illnesses
  • Nappy rash can be prevented by wearing cloth nappies, changing nappies regularly and breastfeeding

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