The Differences Between Measles and Chickenpox
Measles and chickenpox are acute infectious diseases of viral origin that usually appear during childhood. The clinical manifestations of both are very similar, however, they have several individual characteristics that facilitate their detection. Are you interested in knowing the differences between measles and chickenpox? Keep reading!
Viruses are pathogens responsible for major epidemics throughout history. Currently, most viral diseases are preventable through timely vaccination. However, studies confirm that chickenpox and measles are still causing outbreaks in susceptible populations, particularly children.
What are the differences between measles and chickenpox?
The varicella and measles viruses are included among the main agents responsible for exanthematic diseases. They’re generally one of the most common childhood illnesses that present with generalized rashes. Most of these conditions are benign and usually go away on their own.
At the same time, both illnesses show individual properties in terms of their pathogenesis and symptoms, which are usually evident during a professional examination. For this reason, it’s possible to point out the following differences between measles and chickenpox.
1. The virus responsible for the disease
The pathogen responsible for measles and chickenpox is the factor that determines most of the differences between the two diseases. In this regard, measles is caused by a small single-stranded RNA virus, which belongs to the genus Morbillivirus and to the family Paramyxoviridae. This virus has 23 genotypes, with humans being its only reservoir.
On the other hand, the varicella-zoster virus (VZV) belonging to the Herperviridae family is the causative agent of chickenpox. It’s a large and complex double-stranded DNA virus whose exclusive host is humans. Both microorganisms show an affinity for the skin, however, measles has a greater fixation by immune cells and chickenpox by nerve cells.
2. Route of infection
The route of infection is the means that viruses use to come into contact with susceptible people. Measles is very contagious and is spread by droplets from the nose and mouth. These are dispersed into the air when the person coughs and sneezes, and even when they speak. The virus enters through the nose and conjunctiva of the healthy person.
VZV also uses respiratory secretions as a means of transmission between people. However, the main route of transmission of chickenpox is through direct contact with the rashes of the infected person. This virus can penetrate through the mucosa or through small lesions on the skin of the healthy host.
In addition, the varicella-zoster virus is capable of crossing the placenta and even secreting itself into breast milk. These transmission routes determine the congenital and perinatal presentation of the disease. Infection of the fetus during the first 20 weeks of gestation conditions an increased risk of malformations and neurological complications.
3. Incubation and contagion period
The incubation period refers to the time it takes for the virus to colonize, reproduce, and cause the first symptoms of the disease. In the case of measles, this period varies from 9 to 11 days after contact with an infected patient. The infection is common in children between 3 to 5 years old and in immunocompromised people, such as patients with leukemia or malnutrition.
On the other hand, chickenpox has an incubation period of 10 to 21 days after colonization by the virus. This period may vary depending on the immune status and the age of the affected person. Some studies claim that chickenpox is more common in children ages 1 to 9.
The period of contagion refers to the period of time in which the sick person can infect others. In this regard, measles has greater transmissibility when the first symptoms of the disease appear and in the first 2 days after the onset of the eruption. Chickenpox is contagious 1 to 2 days before the rash and up to 5 days after it.
4. Initial symptoms
The symptoms that appear prior to skin lesions usually determine great differences between measles and chickenpox. In general, they’re of clinical relevance for the treating physician as they facilitate the differential diagnosis.
Measles usually begins with a high fever of 102.2 and 104 degrees Fahrenheit, as well as general malaise, rhinitis, swollen lymph nodes, and conjunctivitis. Similarly, people have an irritating cough that goes away after 1 to 2 weeks. Köplik lesions are whitish spots inside the mouth, characteristic of measles.
However, the initial symptoms of chickenpox can be very mild and may not even appear. These include low-grade fever, malaise, and headache.
5. Characteristics of the rash
Rash is the characteristic skin lesion of both viral infections.
Measles manifests as a reddish maculo-papular rash 3 to 4 days after the onset of the disease. It appears behind the ears and projects to the rest of the body.
It usually takes 2 to 3 days for the measles rash to reach and cover the extremities, without affecting the palms of the hands or the soles of the feet. These lesions are accompanied by an increase in the intensity of the rest of the symptoms. In addition, the rash tends to peel in some areas and its color doesn’t disappear when pressure is applied to the skin.
The chickenpox rash is a bit more complex. It originates in the scalp and neck and then spreads very quickly to the rest of the body. The rash begins as small, itchy pink spots that progress to lumps and then fluid-filled vesicles. The vesicles take 5 to 6 days to become scabs.
6. Treatment and prevention measures
The treatment of both measles and chickenpox is very similar. Doctors aim to correct the fever with antipyretics, as well as address the headache and general malaise with pain relievers. Similarly, patients should maintain bed rest and maintain a soft diet with the ingestion of plenty of fluids.
Currently, there’s no effective medicine to fight the measles virus. However, chickenpox can be treated with the administration of acyclovir. Additionally, professionals may prescribe oral antihistamines and topical calamine lotions to relieve the itching.
Both viral diseases can be prevented with the use of vaccines. The live attenuated Moraten, Schwarz, and viral trivalent vaccines are used in immunization against measles. On the other hand, studies suggest that the varicella vaccine shows greater than 85% efficacy against VZV infections.
7. Complications and adverse effects
The varicella-zoster virus is capable of remaining latent in the human body after a first infection. It’s stored in the nerve cells of the dorsal root ganglia and in the cranial nerves. Therefore, it can reactivate and trigger shingles, characterized by a very painful rash on the chest.
Similarly, chickenpox can cause other complications, such as skin and soft tissue infections, pneumonia, encephalitis, myocarditis, and coagulopathies. Measles infection makes a person immune for life. However, the virus can promote complications such as otitis, laryngitis, pneumonia, and diarrhea.
Two diseases of great relevance in childhood
Measles and chickenpox are part of the group of exanthematic viral diseases of childhood. Both diseases are preventable by vaccines, so immunization is the most effective way to prevent their development. Professionals recommend a medical consultation when recognizing any symptoms of either disease.
Generally, the main differences between measles and chickenpox are the clinical manifestations. In this regard, physicians should consider general symptoms and fever.
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