Introduction

Have you ever wondered what is the link between chickenpox and shingles? The answer may surprise you. The same virus is responsible for both infections.

Shingles and chickenpox often confuse and raise questions about who can contract them, and how they can occur and are related. Understanding the differences can allow better identification and management of the conditions.

What is chickenpox?

Chickenpox is a highly infectious illness caused by a virus called the varicella-zoster virus (VZV). It is characterized by itchy skin rash.¹ These rashes can result in blisters and form scabs over, causing some discomfort for those infected. 

Symptoms

The most notable symptom of chickenpox is the skin rash, which occurs in 3 stages;

1. First appearance of rash - small spots appear around the body, most often on the chest and back first but can be anywhere on the body
2. Spots become blisters - spots become bigger and fill up with fluid and may burst. This is the stage that causes the most discomfort and itchiness
3. Spots heal - blisters heal over and become scabs 

The infectious window begins a few days before spots start to show until the last blister scabs over, typically 6-7 days.²

Other symptoms 

• Fever 
• Loss of appetite 
• Headache 
• Stomach ache 
• Sore throat 

These symptoms may occur before or after the rash, or not at all. 

Check if it's chicken pox -> Advice for identification is available here. 

Who is at risk?

Chickenpox is more common in children than adults. In childhood, it is often a mild disease that clears up within a few weeks.³ Since chickenpox in adulthood can be more severe, it was often common practise to allow children to deliberately catch chickenpox early on, with “chickenpox parties”, allowing them to obtain their natural immunity.⁴

Other groups which have a higher risk of complications are immunocompromised individuals and women in pregnancy who have not had chickenpox.

Complications

Although symptoms between children and adults are similar, the risk of complications is greater, with adult chickenpox being 25 times more fatal than in children.⁶ It is not fully understood why adults suffer more from the chickenpox virus than children, but it is theorised to be due to differences in immune system development.

Additionally, adults have more habits that can make them susceptible to complications, such as smoking which can worsen respiratory symptoms like pneumonia. 

More information about chickenpox during pregnancy is available here.

What is shingles?

Shingles, also known as herpes zoster, is a painful rash on the skin, caused by viral infection spread to the central nervous system through the nerves.⁷

Symptoms 

Similar to chicken pox, shingles is characterised by a rash, but one more severe and painful than chickenpox, which can be described as;

• Burning
• Tingling
• Blistering
• Itching

These rashes usually follow the distribution of nerves and are confined to a part of the body, unlike chicken pox which can be all over the body.⁸

Who is at risk?

Only individuals that have had chickenpox in the past, are at risk of developing shingles. This is due to the chickenpox virus laying dormant in your nerves until it is triggered for reactivation, causing shingles.

Shingles is rare in children, but it can still develop. Since it manifests when the chickenpox virus reactivates, many children don’t experience shingles until adulthood. The exception may be a result of exposure to chickenpox during pregnancy, development of chickenpox early on as a baby, or a weakened immune system.⁹

Complications 

Postherpetic neuralgia 

Post-herpetic neuralgia (PHN) is the most common chronic condition following a shingles outbreak. It consists of ongoing pain in the nerve endings where the shingles rash occurred after other symptoms have disappeared.¹⁰

The most at-risk groups are people over 60 and immunocompromised individuals. One study estimates that 14.3% of patients develop PHN a month after their shingles outbreak.¹¹ 

Other complications can include;

• Skin infections
• Vision loss
• Facial paralysis - Ramsay Hunt Syndrome¹²
• Sepsis

Varicella-zoster virus

Varicella-zoster virus (VZV) is a member of the viral family Herpesviridae. Viruses causing cold sores (HSV1) and sexually-transmitted herpes (HSV2) belong to the same category. VZV is responsible for causing both chickenpox and shingles, but their disease mechanisms are different.

How does a virus work?

A virus is an infectious, microscopic organism that can not reproduce on its own, and instead must parasitically infect a host to grow and spread infection. The more viral material there is in the body, the more overwhelmed the immune system becomes and infection becomes harder to fight off.

Primary infection - chickenpox 

The initial infection of VZV occurs in various steps, summarised in the following figure.

Secondary infection - reactivation - shingles

After a chickenpox infection has occurred and subsided, the VZV lies inactive in the sensory ganglia, this trait is called latency. These ganglia are part of the peripheral nervous system and transmit sensory information, such as touch and pain, to the central nervous system. If the virus gets reactivated, it can travel through the nerves and present itself on the skin as a painful rash, known as shingles.

Shingles isn’t something you can catch from someone else; it’s just the chickenpox virus waking up in your body again. However, if you have never had chickenpox or the vaccine, you can catch chickenpox from the fluid-filled blisters of someone with shingles, as these still contain the varicella-zoster virus.

Triggers of shingles

Varicella virus gets reactivated when the immune response decreases, meaning the body is not fighting back as much as it should be.¹⁴

Shingles may appear when you are:

• Feeling unwell - suffering from other viruses such as the common cold 
• On immunosuppressant drugs - these may include medications used in cancer treatments or for auto-immune diseases¹⁵

So do we ever fully recover from chickenpox or shingles?

Yes, you do recover from chickenpox and shingles as these subside after a few weeks of symptoms. However, the virus will stay in the body for life. The good news is that the chances of getting shingles for a second time are less than 6%.¹⁶

Prevention

Chickenpox vaccine 

In the UK, a varicella vaccine is available, but only to those in close contact with immunocompromised individuals, and healthcare workers, to protect those most susceptible to the worst of the illness.

A routine vaccine for the UK has been considered in the past, but since the severe incidence of Varicella is less than 120 cases per year,¹⁷ most of which from children with underlying health conditions, it is not cost-effective to implement an immunisation programme nationwide.

Shingles vaccine 

Since shingles infection is more aggressive than chickenpox, especially for the elderly, it is routinely offered to those over 65 in the UK.¹⁸

Additionally, those with weakened immune systems can get the vaccine too. 

It is important to talk to your healthcare provider if you think you’d benefit from the vaccine. 

Treatment

Home remedies

For most people, treatment will involve staying home, getting plenty of rest, and using pain management methods. 

In the case of more severe illness, it is recommended to visit a GP for antiviral medication, which can ease symptoms and speed up recovery. 

FAQs

Can I get chickenpox twice?

Yes. It is possible but rare to have chickenpox twice. This most commonly occurs in children who have chickenpox very young or in individuals with weakened immune systems.

Can I get shingles twice?

Yes, shingles can be recurrent since the virus stays within the body for life, but is not common to occur more than twice.

If I had chickenpox in childhood, am I protected against Shingles as an adult?

No, shingles is the reactivation of the varicella-zoster virus which is obtained from the initial chickenpox virus. This can be reactivated at any time later in life.

Is shingles infection contagious?

No, it is not possible to get caught by shingles as this is not contagious. It is a reactivation of the varicella-zoster virus caused by other factors such as immunosuppression or other pre-existing conditions making you susceptible.

However, you may catch chickenpox from an individual suffering from shingles if you have never had chickenpox or the vaccine before.

Summary 

Understanding the relationship between chickenpox and shingles allows us to be better informed about our health, more knowledgeable about vaccine options and play our part in the reduction of outbreaks. Establishing the connection between the varicella-zoster virus and the two illnesses gives insight into the mechanisms of these diseases. This allows suitable prevention advice to be established to protect the most vulnerable of our population, contributing to overall public health.