Childhood diseases

When you follow the immunization schedule to protect your child and watch out for symptoms of other common infections, you generally don't need to worry about childhood diseases. Learn more about vaccinations and how they protect your child.

Vaccinations for childhood diseases

Children receive a number of vaccines starting at a young age to protect them against common childhood diseases. Vaccination isn’t mandatory but is strongly recommended by health care professionals to help children avoid diseases that can be very serious and even fatal. Thanks to vaccines, what were once common childhood illnesses, like the measles or rubella, have become virtually non-existent in North America, and smallpox has been eradicated.

The Québec Immunization Program covers vaccines for the following childhood illnesses for children under 18:

  • pertussis (whooping cough)
  • diphtheria
  • rotavirus (causes gastroenteritis)
  • flu (influenza)
  • hepatitis A and B
  • meningococcal C infections
  • pneumococcal infections
  • haemophilus influenzae type b (Hib) infections
  • human papilloma virus (HPV) infections
  • mumps
  • poliomyelitis
  • measles
  • rubella
  • tetanus
  • varicella (chickenpox)

You need to follow the recommended immunization schedule, as each vaccine is given when children need this particular protection the most. You can have your child vaccinated during doctor’s visits, during school immunization days, or at your CLSC. Vaccines covered under the Québec Immunization Program are provided free of charge.

Immunization schedule



2 months

Combination vaccine against diphtheria, whooping cough, tetanus, hepatitis B, poliomyelitis and Hib; pneumococcal vaccine; rotavirus vaccine.

4 months

Same vaccines (booster).

6 months

Same vaccines (booster), except hepatitis B; flu vaccine.*

12 months

Combination vaccine against measles, mumps and rubella (MMR); meningococcal C vaccine; pneumococcal vaccine.

18 months

Combination vaccine against diphtheria, whooping cough, tetanus, hepatitis B, poliomyelitis and Hib (booster); combination vaccine against measles, mumps, rubella and chickenpox (MMRV) (MMR booster).

4 to 6 Years

The chickenpox vaccine only (booster); combination vaccine against diphtheria, whooping cough, tetanus and poliomyelitis (booster).

4th year of primary school

Vaccine against hepatitis B (also protects against hepatitis A); vaccine for HPV infections (for girls only).

3rd year of high school

Meningococcal C vaccine (booster); combination vaccine against diphtheria, whooping cough and tetanus (booster).


* The flu vaccine must be given each fall from the ages of 6 months to 2 years. This vaccine may also be recommended after the age of 2 for children with certain health conditions (e.g., asthma, diabetes or another chronic disease).



Common childhood diseases

Immunization prevents most childhood diseases, but there are some for which a vaccine doesn't exist. These include roseola, fifth disease, hand-foot-and-mouth disease, croup, and bronchiolitis.

Although these diseases generally aren't serious, consult a doctor if your child:

  • Is under the age of 6 months and has a fever. 
  • Has a rectal fever over 39 °C (102 °F).
  • Has had a fever for over 72 hours.
  • Is particularly grumpy, difficult or irritable.
  • Is particularly sleepy or lethargic or doesn’t respond to noise or visual stimulation.
  • Has a wheezing or persistent cough.
  • Has a fever, a rash, or other signs of illness that worry you. 


Roseola, or “sixth disease,” generally strikes children from the ages of 6 to 24 months. It appears 5 to 15 days after contact with an infected child. The main symptom is a high fever (39 °C), although 2 out of 3 children won't have a fever. After about 3 days, the fever may be followed by a pink rash on the chest, abdomen, back, and sometimes the limbs and forehead. A child is contagious only during the fever.

Roseola goes away on its own in less than 7 days without medication. You can lower the fever with acetaminophen or ibuprofen (see note below). A very high fever (39.4 °C or above) requires an emergency medical consultation, as it can cause seizures. 

Watch out!
You must never give ibuprofen to children under 6 months of age without medical advice. You also can’t give acetylsalicylic acid (aspirin) to a child under the age of 16. 

Fifth disease

Fifth disease is a common infection in children aged 4 to 10. They contract it by inhaling droplets when an infected person coughs or sneezes or through contact with contaminated objects. Almost 3 out of 4 people will develop symptoms within 4 to 14 days after contact with the virus. Red patches appear on the cheeks, forearms, trunk, and sometimes the thighs. These symptoms last about 5 to 10 days. The disease is contagious from 1 to 5 days before the rash appears. Once children have symptoms, they are no longer contagious. Pregnant women should avoid contact with infected people, as the virus can spread to the fetus and affect its development.

There is no vaccine or treatment for this virus. The fever can be lowered with acetaminophen or ibuprofen (see note above). Various methods can help relieve the itching cause by the rash: give your child a warm bath with colloidal oatmeal, or apply cold compresses or a thin layer of hydrocortisone cream to the rash. Avoid exposure to heat and the sun, as these can trigger rashes and itching. Antihistamines are not advised for this type of itching. Ask your pharmacist about the best product for your child. 

Hand-foot-and-mouth disease

This harmless but very contagious infection mainly develops in children aged 6 months to 10 years, although adults can also contract the virus. It is spread through contact with the sores of an infected person or from touching a contaminated surface. 

After contracting the virus, the child may get a sore throat and a slight fever 3 to 6 days later. Small red or grey fluid-filled blisters will then develop on the palms of the hands, the soles of the feet, or other parts of the body. Sores can also appear in the mouth. These outbreaks are often very painful. Children are very contagious while the sores are present. The virus will also remain in the stool from 8 to 12 weeks after the sores appear.

The disease goes away on its own in 7 to 10 days. The only treatment is to control the fever and give your child plenty of fluids to prevent dehydration.


Croup, or “false croup” in children under 5 or “laryngitis” in older children, is a viral infection of the throat and vocal cords that is common in children. They contract the virus through direct contact with an infected person, by inhaling droplets that are sneezed or coughed into the air, or by touching a contaminated surface. Symptoms first appear as a cold, and then a fever and cough appear. Children will get a severe cough that gets worse at night and that sounds like barking, and they can develop high-pitched and raspy wheezing. The child may also have trouble breathing. Croup normally goes away on its own in 5 to 7 days.

The recommended treatment is a lot of steam or moisture to relieve the cough and help your child breathe. For example, you can put a cool-mist humidifier in your child's room. If you don’t have one, take your child outside to breathe in some fresh air for 15 minutes. Another remedy is to run the hot water in the shower and sit in the bathroom with your child for 15 minutes with the door closed. 

Acetaminophen or ibuprofen can help control the fever. Irrigating the nasal passages with a saline rinse can also help improve your child's breathing. Avoid giving your child cough or cold syrup without medical advice. Medications may be necessary for more serious cases of croup.

Consult a doctor if your child:

  • has a very severe cough
  • has had a fever for over 72 hours
  • is under the age of 6 months and has a fever
  • has trouble breathing
  • has blue lips
  • has had symptoms for over 7 days 

Bouts of croup tend to come back. To prevent them, keep the child's room humidified as soon as they develop a cold or the flu. 


Bronchiolitis is an infection of the bronchioles (the small branches of the bronchi) that is caused by various viruses. It occurs mostly before the age of 6 months but can appear up to the age of 3 years. It is transmitted through secretions (from coughing or sneezing or on infected objects). Bronchiolitis generally appears less than a week after contact with an infected person. Children will first get symptoms of a cold (congestion, runny nose, cough, sore throat). After a few days, their breathing will turn into wheezing. They will have a slight fever and may vomit and get diarrhea, which can lead to dehydration. 

Bronchiolitis can go away on its own. However, some children need to be hospitalized to receive oxygen and bronchodilators and to treat their dehydration. The acute phase lasts about 3 days, but the cough may persist for another 1 to 3 weeks. Children will be contagious before the onset of symptoms and can remain contagious for a few days afterward.

For more information about these diseases, don’t hesitate to consult your doctor or pharmacist.

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