Monkeypox vs chickenpox: What are the symptoms and how can I tell the difference?

Monkeypox blisters on a hand
There have been more than 3,000 monkeypox cases in the UK since May 2022. Credit: PA Images

The UK has seen a rise in cases of monkeypox - a rare infection most commonly found in west or central Africa.

There have been more than 3,000 cases in the UK since the start of the outbreak in May 2022.

Monkeypox can be difficult to diagnose, according to medics, as it may appear similar to other infections - particularly chickenpox.

They have some symptoms in common, including small blisters filled with fluid, a high temperature, and aches or pains.

But what are the primary differences between the two infections - and are they transmitted differently? We take a look at the guidance from health officials.

Chickenpox is more common and contagious in the UK than monkeypox

Chickenpox is a common illness that mostly affects children, although you can get it at any age. It is possible to have chickenpox more than once, but unusual.

Chickenpox is highly contagious and can be contracted by being in the same room as someone who is infected with it. It is also spread by touching items that have fluid from the blisters on them.

By contrast, a relatively small number of people in the UK have been diagnosed with monkeypox.

According to government guidance, the risk of contracting monkeypox remains low as it "does not generally spread easily" between people.

Images of individual monkeypox lesions. Credit: PA Images

Monkeypox can be passed from person to person through any direct (skin-to-skin) contact with the blisters or scabs - including during sexual contact, kissing, cuddling or holding hands.

It can also be spread via contaminated objects, such as towels, clothing or bedding, or if someone with the infection coughs or sneezes near you.

Anyone can get monkeypox, but currently most UK cases have been in men who are gay, bisexual, or have had sex with other men.

The NHS says you are extremely unlikely to have monkeypox if:

  • You have not been in close contact with someone who has monkeypox or has monkeypox symptoms, including touching their skin or sharing towels, clothes or bedding.

  • You have not recently travelled to west or central Africa.

Monkeypox and chickenpox are caused by different viruses

Monkeypox is caused by monkeypox virus - a member of the Orthopoxvirus genus in the Poxviridae family.

Chickenpox is caused by the varicella-zoster (VZV) herpes virus.

Monkeypox symptoms can differ slightly to chickenpox

The World Health Organization (WHO) says monkeypox can present itself in a similar way to other rash illnesses, including chickenpox.

Both monkeypox and chickenpox can result in raised spots, which turn into small blisters filled with fluid. These blisters eventually form scabs, which later fall off.

They also have some other symptoms in common, including a high temperature, aches and pains, and feeling generally unwell.

But according to WHO, one early symptom of monkeypox is swollen lymph nodes or glands - known medically as lymphadenopathy - which may help to distinguish it from chickenpox. Common places to check for swelling of the lymph nodes include the neck, armpit, chest, abdomen, and groin.

Research also suggests that monkeypox patients may experience fever before the blisters erupt, and that the lesions may take longer to develop.

Other symptoms of monkeypox listed on the NHS website include headache, muscle aches, backache, chills or exhaustion. Those infected may also experience anal pain or bleeding from their bottom.

Symptoms of monkeypox typically last from two to four weeks.

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There are differences in guidance for monkeypox vs chickenpox

If you are infected with monkeypox, it usually takes between five and 21 days for the first symptoms to appear, according to the NHS website.

A rash usually appears one to five days after the first symptoms of monkeypox, often on the face, groin or hands, before spreading to other parts of the body.

The illness is usually mild and most of those infected will recover within a few weeks without treatment, although you may be advised to self-isolate at home.

The risk of needing hospital treatment is higher in older people, younger people, or if your immune system is affected by a condition or medication.

If you suspect you have monkeypox, the NHS advice is to call a sexual health clinic as soon as possible. If you are unable to contact a clinic, call 111 for guidance. Stay at home and avoid close contact with others until you have been told what to do.

With chickenpox, the spots start appearing around one to three weeks after catching it.

The person with chickenpox will need to stay away from school, nursery or work until all the spots have formed a scab.

Chickenpox usually gets better by itself after a week or two, and can often be treated without needing to see a doctor.

There is plenty of advice on the NHS website for treating chickenpox at home, but if you are unsure of the diagnosis, or if you are concerned, seek medical advice from your GP.

The NHS says there are certain cases with chickenpox where you should always seek immediate medical advice from your GP or 111. These include:

  • If you're pregnant and have not had chickenpox before, or aren't sure, and you have been near someone who has it

  • If you have a weakened immune system and have been near someone with chickenpox

  • If you think your newborn baby has chickenpox

There are signs that the monkeypox outbreak in the UK has recently plateaued. Credit: PA Images

Is there a risk of monkeypox to children?

If a child is showing symptoms of monkeypox and there is reason to believe they may have contracted the infection, the NHS advises calling a GP or 111.

This includes if the child has been in close contact with someone who has, or might have, monkeypox in the past three weeks, or if the child has recently been to west or central Africa.

Is monkeypox still spreading throughout the UK?

There are signs that the monkeypox outbreak in the UK has plateaued, according to one health leader.

Dame Jenny Harries, chief executive of the UK Health Security Agency, said cases have decreased over the last few weeks.

Speaking to BBC Radio 4’s Today programme earlier last week, Dame Jenny said: "We have some early signs, we hope – always remaining vigilant and cautious – that the outbreak in this country is actually plateaued and over a four-week period has started to steadily decrease.

"A couple of weeks ago it was 35 cases a day, now it’s around 20 cases a day."