Measles infection takes around 10 days to manifest as apparent symptoms. The symptoms may last for around 2 weeks before finally resolving on their own. The measles rash usually appears a few days afterwards.
Symptoms of measles infection in its initial phases include:-
Influenza or common cold like symptoms including runny nose, watery eyes, sneezing etc.
There are swollen eyes and eyelids and the eyes are red and sensitive to light as well. This is known as conjunctivitis.
There may be a mild to severe rise of temperature. Peaks may be over 40.6C (105F) especially in children and peaks keep occurring for several days. The temperature normalizes only to rise again when the rash appears
Weakness, irritability and refusal to eat in a child
Muscle pain and aches
Small pin-head size greyish-white spots (called Koplik's spots) in the mouth and throat. These develop within two days of appearance of symptoms. These may develop on the inside lining of the cheeks, so they are difficult to see.
The spots typically occur opposite the second molar teeth as small, red spots, each with a bluish-white speck in the centre. They occur in 60-70% of patients during the initial phase and remain up to 2-3 days after the rash disappears.
The measles rash
These are reddish brown spots. The measles rash appears two to four days after initial symptoms and lasts for up to eight days. The rash usually starts behind the ears, spread around the head and neck, then spreads to the legs and the rest of the body.
The spots are small and distinct initially but soon get bigger and join together. At later stages the rash becomes blotchy and confluent. It fades after three to four days and may peel off after a week or so. It leaves behind a brownish discoloration, sometimes accompanied by fine peel-offs.
There may be nausea and vomiting, abdominal pain and diarrhoea.
Complications of measles
In most cases the measles infection passes without severe complications. In some children however there may development of complications. These complications may be debilitating or even life threatening. These include:-
Ear infections otitis media
Lung infections – pneumonia
Liver infections – hepatitis
Eye inflammation – Conjunctivitis
Inflammation of the brain – encephalitis. This is very rare and may develop a few days after the rash has appeared, and a quarter of those who get this complication will be left with brain damage. A devastating but extremely rare progressive illness called subacute sclerosing panencephalitis (SSPE) may occur many years after the first episode of measles and is usually fatal. It is rare and affects less than one in 100,000 cases.
Complications involving the nervous system