Measles

Measles is a highly infectious viral illness that can be very unpleasant and sometimes lead to serious complications. It's now uncommon in the UK because of the effectiveness of vaccination.

Anyone can get measles if they haven't been vaccinated or they haven't had it before, although it's most common in young children.

The infection usually clears in around 7 to 10 days.

Symptoms of measles

The initial symptoms of measles develop around 10 days after you're infected. These can include:

• cold-like symptoms, such as a runny nose, sneezing, and a cough
• sore, red eyes that may be sensitive to light
• a high temperature (fever), which may reach around 40C (104F)
• small greyish-white spots on the inside of the cheeks

A few days later, a red-brown blotchy rash will appear. This usually starts on the head or upper neck, before spreading outwards to the rest of the body.

Read more about the symptoms of measles

Measles starts with cold-like symptoms that develop about 10 days after becoming infected. This is followed a few days later by the measles rash.

For most people, the illness lasts around 7 to 10 days in total.

Initial symptoms

The initial symptoms of measles can include:

• a runny or blocked nose
• sneezing
• watery eyes
• swollen eyelids
• sore, red eyes that may be sensitive to light
• a high temperature (fever), which may reach around 40C (104F)
• small greyish-white spots in the mouth (see below)
• aches and pains
• a cough
• loss of appetite
• tiredness, irritability and a general lack of energy

Spots in the mouth

A day or two before the rash appears, many people with measles develop small greyish-white spots in their mouth.

Not everyone with measles has these spots, but if someone has them in addition to the other symptoms listed above or a rash, it's highly likely they have the condition.

The spots will usually last for a few days.

The measles rash

The measles rash appears around two to four days after the initial symptoms and normally fades after about a week.

You'll usually feel most ill on the first or second day after the rash develops.

The rash:

• is made up of small red-brown, flat or slightly raised spots that may join together into larger blotchy patches
• usually first appears on the head or neck, before spreading outwards to the rest of the body
• is slightly itchy for some people
• can look similar to other childhood conditions, such as slapped cheek syndrome, roseola or rubella
• is unlikely to be caused by measles if the person has been fully vaccinated (had two doses of the MMR vaccine) or had measles before

When to seek medical advice

Contact your GP as soon as possible if you suspect that you or your child has measles, even if you're not completely sure.

It's best to phone before your visit, as your GP surgery may need to make arrangements to reduce the risk of spreading the infection to others.

You should also see your GP if you've been in close contact with someone who has measles and you've not been fully vaccinated or haven't had the infection before – even if you don't have any symptoms yet.

Most people will recover from measles after around 7 to 10 days, but sometimes it can lead to serious complications.

It's estimated around 1 in every 5,000 people with measles will die as a result of the infection.

Who's most at risk?

Complications of measles are more likely to develop in certain groups of people, including:

• babies younger than 12 months old
• people with a weakened immune system - such as those with leukaemia, receiving cancer treatment or taking certain medication
• pregnant women

Children who are older than 12 months and otherwise healthy have the lowest risk of developing complications.

Common complications

More common complications of measles include:

• diarrhoea and vomiting, which can lead to dehydration
• middle ear infection (otitis media), which can cause earache
• eye infection (conjunctivitis)
• inflammation of the voice box (laryngitis)
• pneumonia, bronchitis and croup – infections of the airways and lungs
• fits caused by a fever (febrile seizures)

About 1 in every 15 children with measles will develop complications like these.

Uncommon complications

Less common complications of measles include:

• liver infection (hepatitis)
• misalignment of the eyes (squint) – if the virus affects the nerves and muscles of the eye
• infection of the membranes surrounding the brain and spinal cord (meningitis) or infection of the brain itself (encephalitis)

Rare complications

In rare cases, measles can lead to:

• serious eye disorders, such as an infection of the optic nerve, the nerve that transmits information from the eye to the brain – this is known as optic neuritis and can lead to vision loss 
• heart and nervous system problems
• a fatal brain complication known as subacute sclerosing panencephalitis (SSPE), which can occur several years after measles – this is very rare, occurring in only 1 in every 25,000 cases

Pregnancy complications

If you're not immune to measles and you become infected while you're pregnant, there's a risk of:

• miscarriage or stillbirth
• your baby being born prematurely – before the 37th week of pregnancy
• your baby having a low birth weight

If you're pregnant and you think you've come into contact with someone with measles and you know you're not immune, you should see your GP as soon as possible. They can advise you about treatment to reduce your risk of developing the condition.

Read more about preventing measles.

When to seek immediate medical advice

Go to your nearest accident and emergency (A&E) department or call 999 for an ambulance if you or your child have measles and develop:

• shortness of breath
• a sharp chest pain that feels worse with breathing
• coughing up blood
• drowsiness
• confusion
• fits (convulsions)

These symptoms:

• might be a sign of a serious infection requiring admission to hospital
• could be viral (pneumonitis for example), rather than bacterial in origin

You can avoid catching measles by having the measles, mumps and rubella (MMR) vaccine.

If the MMR vaccine isn't suitable for you, a treatment called human normal immunoglobulin (HNIG) can be used if you're at immediate risk of catching measles.

MMR vaccine

Routine vaccination

The MMR vaccine is given as part of the routine NHS childhood vaccination programme. One dose is usually given to a child when they're 12 to 13 months old, and a second dose is given from age 3 years 4 months.

Contact your GP if you are uncertain about whether your child's vaccinations are up-to-date.

You or your child can be vaccinated at any point if you haven't been fully vaccinated before. If you're not sure whether you were vaccinated in the past, having the vaccine again won't cause any harm.

Special circumstances

A dose of the MMR vaccine can also be given to anyone over six months of age if they're at an immediate risk of catching measles. For example, this could be if:

• there's an outbreak of measles in your local area
• you've been in close contact with someone who has measles
• you're planning on travelling to an area where the infection is widespread

Children who have the vaccine before their first birthday should still have the 2 routine doses at age 12 months and from age 3 years 4 months.

Human normal immunoglobulin

Human normal immunoglobulin (HNIG) is a special concentration of antibodies that can give short-term but immediate protection against measles.

It may be recommended for people in the following groups if they've been exposed to someone with measles:

• all babies under 6 months of age, and some babies aged 6 to 8 months
• pregnant women who haven't been fully vaccinated or haven't had measles before
• people with weak immune systems – for example, those with HIV or people receiving treatment that weakens their immune system, such as treatment for leukaemia

HNIG should ideally be given within six days of exposure.

Stopping measles spreading to others

If you already have measles, it's important to reduce the risk of spreading the infection to other people.

You should:

• avoid work or school for at least four days from when you first developed the measles rash
• try to avoid contact with people who are more vulnerable to the infection, such as young children and pregnant women, while you're ill