Although chickenpox is usually a childhood illness, it can strike adults.

Doctors say the illness tends to be more serious for adults, with potential complications including sepsis, pneumonia and encephalitis (inflammation of the brain).

GP Dr Paul Ettlinger of the London General Practice (thelondongeneralpractice.com) says: “Most people get chickenpox as children, and to get it again as an adult would be very rare as you have antibodies against it.”

You’re more likely to catch it if you didn’t as a child – “Although there is a vaccination for chickenpox”, Ettlinger adds. The chickenpox vaccination isn’t routinely available on the NHS, but it’s recommended for those in close contact with people who have a weakened immune system, or are at risk of serious illness if they catch chickenpox. “

The NHS says an itchy, spotty rash anywhere on the body, including inside the mouth and around the genitals, is the main symptom of chickenpox, which has three main stages in both children and adults:

Stage 1:

Small spots appear, and they maybe painful. They may spread or stay in a small area, and can be red, pink, dark or skin-coloured.

Stage 2:

The spots fill with fluid and become blistered and very itchy.

Stage 3:

The blisters scab over.

During the illness, people might also ache and have a high temperature, lose their appetite and generally feel ill.

Adults will usually have more spots than children, too.

As chickenpox is very contagious, the NHS recommends adults stay off work until all their spots have scabbed over – usually taking about five days after they first appear. In the meantime, drink plenty of fluids, take paracetamol, and try to not scratch the spots, as they could leave scars.

Try using cooling creams or gels, or speak to a pharmacist about taking antihistamines to help the itching. You could also bathe in cool water and pat the skin dry – but be careful not to rub it.

The NHS warns people with chickenpox not to use ibuprofen as it may cause serious skin infections – and don’t go near newborn babies, pregnant women or people with a weakened immune system.