Health Info > Infections Published on : April 16, 2025

What is the difference between measles and chickenpox?

Written by the editorial staff writer at Hola. Medically Reviewed by Dr. Ammar AL-ANI, MBChB, CCBST, AMC.

What is the difference between measles and chickenpox?

Summary: Measles and chickenpox are infectious viral diseases with different origins and signs. Measles, which is caused by the measles virus, results in a high fever, cough, and a red rash that begins on the face and moves downward. Chickenpox, originating from the varicella-zoster virus, causes itchy, fluid-filled blisters that develop in stages. Vaccination can help prevent both illnesses and supportive care can be used to manage them effectively.

Measles and chickenpox are two prevalent childhood diseases caused by different viruses. While they have similar symptoms, they differ in their origins, transmission, and treatment. Understanding the differences between these diseases is important for proper diagnosis, prevention, and treatment. Let’s examine the key differences between measles and chickenpox, including their origin, symptoms, complications, and preventative measures.

What is measles?

Measles is a viral infection that is extremely contagious and is caused by the paramyxovirus. It is transmitted through respiratory droplets released when an infected person coughs or sneezes. The illness presents symptoms such as a high fever, cough, runny nose, red eyes, and a unique red rash that begins on the face and spreads to other parts of the body. Measles can result in serious complications, including pneumonia, encephalitis (inflammation of the brain), and dehydration. The most effective preventative measure is vaccination.

Also read: Measles: Symptoms, how it spreads, when to call a GP

What is chickenpox?

Chickenpox, which is caused by the varicella-zoster virus (VZV), is also a contagious viral infection. It spreads through direct contact with an infected person or through airborne droplets. Symptoms include itchy red blisters that arise in stages, fever, fatigue, and body aches. While the disease is usually mild in children, it can be more severe in adults. Vaccination offers reliable protection against this infection.

Measles and chickenpox: Key difference

Measles:

Measles is a highly contagious viral infection stemming from the paramyxovirus that mainly spreads via respiratory droplets. It targets the respiratory system before disseminating throughout the body, resulting in fever, cough, and a distinctive red rash. Measles can lead to serious complications, including pneumonia, encephalitis, and dehydration. The MMR (measles, mumps, rubella) vaccine is the most effective means of preventing infection.

Chickenpox:

Chickenpox, caused by the varicella-zoster virus (VZV), is transmitted through direct contact and airborne routes. It mainly impacts the skin, resulting in an itchy rash with blisters, along with symptoms like fever and fatigue. While it is generally mild in children, chickenpox can be more serious for adults and those with weakened immune systems. The varicella vaccine offers robust protection against the disease and lowers the risk of complications.

Measles vs Chickenpox: Symptoms

Measles: Measles starts with a high fever, cough, runny nose, and red, watery eyes, followed by small white spots inside the mouth known as Koplik’s spots. A red blotchy rash develops a few days later, beginning on the face and then spreading downwards. The illness often includes fatigue and body aches, with complications such as ear infections and pneumonia potentially occurring.

Chickenpox: In contrast, chickenpox begins with fever, fatigue, headache, and loss of appetite, followed by an itchy rash that evolves from red spots to fluid-filled blisters. Unlike measles, the chickenpox rash appears in waves, with new blisters emerging as older ones scab over. The infection typically resolves in about a week, but severe cases can lead to bacterial skin infections or pneumonia.

Measles vs Chickenpox: Rashes

Measles: The measles rash is characterised by flat, red spots that may merge, creating a blotchy appearance on the skin. It starts on the face and behind the ears, gradually spreading to the chest, back, and limbs. This rash typically lasts from 5 to 6 days, and as it fades, the skin may temporarily darken or peel.

Chickenpox: The chickenpox rash initiates as small red spots that quickly escalate into fluid-filled blisters. These blisters cluster across the body, affecting the scalp, mouth, and genitals. They progress through stages of bursting, drying, and forming scabs, generally healing within 7 to 10 days. Unlike measles, the chickenpox rash presents in various stages simultaneously.

Measles vs chickenpox: Incubation & contagious period

Measles: Measles has an incubation period that lasts between 7 and 14 days, during which the virus replicates before symptoms manifest. An infected individual is contagious four days before and for four days following the appearance of the rash. Measles spreads swiftly among unvaccinated individuals, making prompt isolation vital for preventing outbreaks.

Chickenpox: Chickenpox has an incubation period of 10 to 21 days and symptoms can take up to three weeks to develop after exposure. It remains contagious from one to two days before the rash appears until all blisters have crusted over, usually around 5 to 7 days after the rash shows up. This extended contagious period increases the chances of transmission, specifically in schools and households.

Also read: What are signs that your immune system is fighting a virus?

Measles vs chickenpox: Causes

Measles: Measles is caused by the measles virus (a type of paramyxovirus), which is transmitted through aerosolised respiratory droplets released when an infected person coughs or sneezes. It can stay airborne for as long as two hours, making it highly transmissible. Even short exposure in a shared environment can result in infection among individuals who have not been vaccinated.

Chickenpox: Chickenpox is caused by the varicella-zoster virus (VZV) and can be transmitted through direct contact with rashes, airborne transmission, or touching contaminated surfaces. In contrast to measles, this virus can lie dormant within the body after the initial infection and may later reactivate in life as shingles (herpes zoster).

Measles vs chickenpox: Risks

Measles: Measles may result in serious health issues, particularly in young children, pregnant women, and individuals with compromised immune systems. Potential complications include pneumonia, encephalitis (inflammation of the brain), severe dehydration, and even fatalities. Pregnant women who contract measles face an increased risk of miscarriage or premature labour.

Chickenpox: While chickenpox is generally mild, complications can arise, especially among adults, newborns, and those with weakened immune systems. Risks may involve bacterial skin infections, pneumonia, encephalitis, and Reye’s syndrome if aspirin is administered during the illness. Moreover, the virus can remain dormant and later cause shingles, resulting in a painful rash that impacts the nerves.

Measles vs chickenpox: Diagnoses

Measles: Measles diagnosis relies on symptom observation, the appearance of the rash, and specific laboratory tests. A doctor may search for Koplik’s spots within the mouth and verify infection through measles-specific IgM antibodies or RT-PCR analysis of blood or saliva.

Chickenpox: Chickenpox is typically diagnosed based on its distinctive rash. In ambiguous instances, tests such as a varicella-zoster IgM blood evaluation or PCR testing of a blister sample can confirm the diagnosis. Unlike measles, chickenpox is often identifiable without requiring lab tests.

Measles vs chickenpox: Treatment

Measles: There is no specific antiviral therapy for measles, thus, treatment aims to alleviate symptoms. Patients are encouraged to rest, maintain hydration, and use fever-reducing medications such as acetaminophen (Panadol, not aspirin). Vitamin A supplements are advised to minimise complications, particularly in children.

Chickenpox: Treatment for chickenpox involves antihistamines for itch relief, fever reducers (aspirin is avoided), and calamine lotion for skin soothing. In high-risk cases, antiviral medications like acyclovir may be utilised to lessen the duration of the illness. Vaccination with the varicella vaccine is the most effective preventative option.

Aspect	Measles	Chickenpox
Cause	Measles virus (Paramyxovirus)	Varicella-zoster virus (VZV)
Transmission	Respiratory droplets, airborne	Airborne, direct contact with rash
Incubation	7–14 days	10–21 days
Contagious period	4 days before to 4 days after rash	1–2 days before rash until blisters crust over
Key symptoms	Fever, cough, runny nose, red eyes, Koplik’s spots, red blotchy rash	Fever, fatigue, itchy red spots that turn into blisters
Rash pattern	Flat, red spots starting on the face, spreading downward	Blisters appear in waves, various stages at once
Complications	Pneumonia, encephalitis, dehydration	Skin infections, pneumonia, shingles later in life
Diagnosis	Clinical signs, IgM antibody, RT-PCR	Mostly visual; PCR or IgM blood test if needed
Treatment	Supportive care, hydration, vitamin A, fever reducers (not aspirin)	Antihistamines, calamine lotion, antivirals (for high risk), no aspirin
Prevention	MMR vaccine	Varicella vaccine
Risk groups	Infants, pregnant women, immunocompromised	Adults, newborns, immunocompromised
Special notes	Can linger in air for up to 2 hours	Virus can reactivate later as shingles

When to call the doctor?

It's important to seek medical care if symptoms of measles or chickenpox deteriorate or result in complications. For measles, consult a doctor if there is a high fever (exceeding 104°F, 40 Celsius), breathing difficulties, a persistent cough, confusion, or signs of severe dehydration. Infants, pregnant women, and individuals with weakened immune systems are at heightened risk and need careful monitoring. For chickenpox, contact a doctor if a high fever persists for more than four days or if there is a severe rash with pus, breathing difficulties, confusion, or dehydration symptoms. It is essential to seek medical evaluation if the infected person is a newborn, an adult, or someone with a weakened immune system. In addition, if symptoms of shingles occur later on. it’s important to seek medical help promptly to prevent complications.

FAQs

How long does it take to recover from measles or chickenpox?

Generally, individuals start to feel better within one to two weeks with adequate rest and care.

When are measles and chickenpox contagious?

Measles can be transmitted several days before the appearance of the rash and remains contagious for a few days afterwards. Chickenpox is infectious one to two days before the rash appears and until all blisters have dried and formed scabs.

Can adults get chickenpox if they didn’t have it as a child?

Yes, adults who have never had chickenpox or who haven't been vaccinated can still contract it, and the illness tends to be more severe in adults compared to children.

Is it possible to get measles or chickenpox more than once?

It's uncommon, as most individuals gain lifelong immunity after having the disease, though rare cases of reinfection can happen.

Is there a cure for measles or chickenpox?

There is no cure, but managing symptoms and providing supportive care can help alleviate discomfort and avoid complications.

Should you go to work, school, or travel if you have measles or chickenpox?

No, it is advisable to remain at home to avoid transmitting the infection to others.

Can natural remedies or supplements stop measles or chickenpox?

While maintaining a healthy lifestyle can boost immunity, vaccinations are the only proven method to prevent these diseases.

What should you do if you’ve been exposed to someone with measles or chickenpox?

If you are not immune, seek advice from a doctor as soon as possible. A vaccine or other preventative measures may be suggested to lower your risk of infection.

Telehealth with an online doctor

Telehealth services allow people to consult healthcare professionals regarding symptoms of measles and chickenpox from their homes. Hola Health's telehealth platform offers a convenient, reliable way to manage these viral infections. Our services are available around the clock and include:

Telehealth appointments Australia: Patients can connect with skilled doctors to discuss symptoms such as fever, rash, cough, fatigue, and itching. The online doctor will evaluate the case and provide expert advice on symptom management and complication monitoring.
Instant scripts: When necessary, healthcare professionals can electronically prescribe necessary medicines. Patients can pick up medications from local pharmacies or receive same-day delivery.
Doctor referrals: In severe or high-risk situations, doctors can direct patients for additional assessment, blood tests, or referrals to specialists, such as an infectious disease consultant.
Online medical certificates 24/7: If measles or chickenpox symptoms affect work, school, or daily life, Hola Health’s telehealth service can issue medical certificates for the same day or multiple days.

In conclusion, measles and chickenpox are distinct viral infections with unique causes, symptoms, and risks. Both can be effectively prevented through the MMR vaccination for measles and the varicella vaccine for chickenpox. While treatment primarily targets symptom management, vaccination is the most reliable method to protect against these illnesses and their potential complications.

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