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Common Childhood Illnesses

Published on June 5, 2024 at 8:00 / Updated on June 21, 2024 at 8:00

Below is a summary of the most common childhood illnesses, with the exception of the common cold.

Fifth disease(erythema infectiosum)
Parvovirus B19

Begins with cold- or flu-like symptoms (e.g., fever, headache, runny nose, fatigue, muscle aches).

Followed by bright red cheeks (slapped cheek appearance) then a lace-like rash on the trunk and extremities.

About 25% of cases are asymptomatic.


Spread by hands and objects contaminated with secretions from the infected person.

Airborne secretions.

From mother to child during pregnancy.


Symptoms appear 4 to 21 days after exposure to the virus.

Cold symptoms appear first. After 7-10 days, the person's cheeks become flushed and the rash spreads all over the body.

The child is contagious up to 7 days before the rash appears. Once the rash appears, the child is no longer contagious, with the exception of those who are immunocompromised.

Can last up to 3 weeks or more.


No specific treatment.

Do not exclude the child from childcare or school if feeling well enough.

Outbreaks are most common in the winter and spring.

Heat, sunlight and exercise can exacerbate the rash.

Serious complications are rare with fifth disease. However, speak to your doctor if you have any of the following conditions:

  • You are anemic
  • You are immunocompromised
  • You are pregnant
Whooping cough
Bordetella pertussis

Cold-like symptoms

Profuse runny nose

Long coughing spells (often at night)


Crowing or whooping sound


Spread by hands and objects contaminated with secretions from the infected person.

Airborne secretions.

Highly contagious.


Symptoms appear 7 to 10 days (rarely after 14 days) after exposure to the bacteria.

Cold symptoms last for 7-10 days and are followed by a cough.

The child is contagious from the onset of the runny nose until 7 days after starting antibiotic therapy or 3 weeks after the first symptoms appear if left untreated. Children younger than 12 months of age may be contagious for up to 6 weeks.

Usually lasts between 6 and 10 weeks.


Whooping cough is caused by a bacteria and requires antibiotic treatment.

The child should get plenty of rest and drink fluids in small amounts, often.

Children who contract a respiratory tract infection over the course of the next year may develop symptoms that resemble whooping cough.

The pertussis vaccine is part of the routine immunization schedule. It is possible to get whooping cough more than once, even if the child has been vaccinated. If the child has been vaccinated, the infection is likely to be less severe.

Strep throat and scarlet fever
Group A beta-hemolytic streptococci


Sore throat

Nausea and vomiting

Swollen glands in the neck

Rash on the neck, chest and folds of skin that feels like rough sandpaper (scarlet fever)

Strawberry tongue (scarlet fever)


Spread by hands and objects contaminated with secretions from the infected person.

Airborne secretions.


First symptoms appear 3 to 5 days after exposure to the bacteria.

The child is contagious 24 hours after treatment is initiated. If left untreated, the infectious period may last up to 3 weeks.

Rarely lasts longer than 7 days.


The disease is caused by a bacteria and requires antibiotic treatment. Affected individuals should get lots of rest, stay hydrated, and eat soft foods.

The child should be excluded from childcare or school for the first 24-48 hours after the start of antibiotics.

Outbreaks of scarlet fever are most common in the winter and spring.

Scarlet fever is most common among school-aged children.

This illness may be contracted more than once.

Roseola (Exanthem subitum or Sixth disease)
Human herpesvirus type 6

High fever (often > 39.5oC)

Slight runny nose

Sore throat

Swollen lymph nodes in the neck

Small, non-itchy pink blotches on the face, neck, and limbs


Spread by contact with respiratory secretions or saliva from the infected person.

Airborne secretions.

Not very contagious


Symptoms appear 5 to 15 days after exposure to the virus.

The high fever usually lasts for 3 days. Once the fever subsides, pink blotches appear.

The child is probably contagious before the rash and before the other symptoms.

Lasts between 3 and 7 days.


No specific treatment.

The child should get plenty of rest and drink plenty of fluids. Fever reducing medication may be needed.

Children with the disease don't need to stay home from school or daycare.

Mainly affects children between the ages of 6 months and 2 years. There is currently no vaccine available.



Aches and pains

A generalized rash that turns into blisters, which break and crust over



Enters the body through the nose or mouth.

Spread mainly through the air. The virus can survive in the air for several hours.

Also spread by direct contact with the virus (e.g., touching a blister, the liquid or its moist crust) or contaminated objects.

Women who are pregnant can pass it on to their baby during pregnancy.

Very contagious


Symptoms appear 10 to 21 days after exposure.

The person is contagious 2 days before the spots appear and until they have crusted over (approximately 7 days).

The illness usually lasts 7 to 14 days. It takes about 2 weeks for the spots to disappear completely.


Severe cases may require antiviral therapy.

Cold compresses and acetaminophen may also help relieve symptoms.

Keep fingernails short to prevent the child from scratching as it could lead to infection and scarring.

If permitted, the child may go back to childcare or school as soon as he is well enough to participate in normal activities.

Outbreaks are most common in late winter and early spring.

Chickenpox is usually mild and commonly affects young children. Adolescents and adults who contract the disease can become seriously ill.

Pregnant women and people with weakened immune systems who have never had chickenpox should see their doctor right away.

There is a chickenpox vaccine available and it is part of the routine immunization schedule in some provinces and territories.

Since the virus lies dormant after an episode of chickenpox, it may be reactivated later in life, causing shingles.

Streptococcal or Staphylococci

Small red spots that develop into pus-filled blisters that break open and discharge fluid and eventually form a yellowish crust.

The face (around the mouth, nose and eyes) is the most commonly affected area, but it can also appear on the trunk, hands and buttocks.

Occasionally accompanied by fever.


Direct skin contact (infected person) with discharge from the blisters or indirectly (bacteria on towels or clothing)

Indirect contact with clothing, sheet or towel that touched the wound of an infected person.

Bacteria enter the skin through breaks in the skin caused by scrapes, scratches, eczema or insect bites. The infection develops afterwards.


The person is contagious until all the crusts have healed or at least 24 to 48 hours after starting antibiotics.

Impetigo appears 7 to 10 days after exposure.

With adequate treatment, the infection rarely lasts more than 7 days.


Impetigo is caused by a bacteria and requires antibiotic treatment. The treatment may be taken orally or applied as a topical ointment.

Avoid scratching, clean the sores with soapy water, and keep them dry. Trim fingernails to help reduce the risk of spreading the infection.

Exclude the child from childcare or school at least 24 hours after starting antibiotic treatment or until lesions have disappeared if no treatment was given.

It is possible to contract impetigo more than once.

Respiratory syncytial virus


Congestion and runny nose


Loss of appetite and decreased energy


Wheezing or rapid breathing

Otitis (on occasion)

The illness may, on occasion, lead to pneumonia.


Spread by hands and objects contaminated with secretions from the infected person. The virus can survive several hours on toys and on the skin.

Airborne secretions.


Symptoms appear 2 to 8 days after exposure.

People with the disease are particularly contagious 3-8 days after the onset of symptoms, but can infect others for up to 3 weeks.

The acute phase of the infection lasts 3 to 7 days. It takes 1 to 2 weeks to recover completely and may even be as long as 3 weeks.


Most children do not require hospitalization or any specific treatment.

Offer fluids in small amounts more often than usual.

Using salt water (saline) and a bulb syringe may help relieve nasal congestion.

Medications such as acetaminophen may be used to relieve pain and fever.

The child may go to school or childcare if feeling well enough.

Outbreaks are most common in the fall and winter.

Children younger than 2 years of age are most commonly affected, especially infants between the ages of 3 and 6 months.

A child may contract the infection more than once over the course of a season.

Hand-Foot-and-Mouth disease
Coxsackie virus

Small painful sores in the mouth. A skin rash with red spots, and sometimes with blisters that may also develop on the palms of the hands, soles of the feet, buttocks and other parts of the body.

Other symptoms: fever, headache, sore throat, loss of appetite, lack of energy, vomiting and diarrhea.


Through contact with the nose or throat secretions of an infected person (e.g., present on their hands or on an object).

Through contact with infected droplets coughed into the air by an infected person.

Through direct or indirect contact with the stool of an infected person.


Symptoms appear 3 to 6 days after exposure.

Affected individuals are particularly contagious during the first week. The virus is present in the stool for several weeks after symptoms disappear.

The disease usually lasts 7-10 days.


No specific treatment

Drink plenty of water or milk. Avoid juices because they are acidic and may worsen the pain.

Do not pop the blisters.

If necessary, administer medication to relieve pain and fever.

Outbreaks are most common in the summer and early fall.

Mainly affects children aged 6 months to 4 years.

No vaccine currently available

Measles and Rubella

Thanks to routine immunization, cases of measles and rubella are very rare in Canada. These diseases, however, can have serious consequences. Every effort should be made to prevent transmission to unvaccinated individuals and to promote vaccination.

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