Common childhood illnesses are something nearly every Canadian parent will face. Some conditions, like croup or pink eye, show up regularly in schools and daycares across the country. Others, like Kawasaki disease, are rare but serious. This guide walks you through the most important childhood illnesses — what to watch for, how they spread, and when to call your family doctor or visit a walk-in clinic.
Common Childhood Illnesses: An Overview
Thanks to vaccines, many childhood illnesses are far less common than they used to be. However, others still circulate widely, especially in schools and childcare settings. These conditions range from everyday infections to more puzzling diseases that can surprise even experienced parents.
No matter what your child is dealing with, getting the right diagnosis matters. Always check with your family doctor or a walk-in clinic if you are unsure about your child’s symptoms. Your provincial health plan covers most visits, so do not hesitate to reach out.
Respiratory Syncytial Virus (RSV)
Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and pneumonia in young children. It is one of the most common childhood illnesses seen in Canadian emergency rooms every winter. Most children will have had RSV at least once before their second birthday.
RSV Symptoms to Watch For
RSV usually starts with flu-like symptoms: fever, a runny nose, and a cough. In younger children, it can quickly become more serious. Up to 40% of children experience wheezing during their first RSV infection.
In some cases — up to 2% — children need hospital care to manage breathing difficulties. Children typically show symptoms three to five days after being exposed to the virus. Exposure can happen through direct contact with an infected person or by touching contaminated toys and surfaces.
Who Is Most at Risk?
Children under two or three years old face the highest risk of serious RSV symptoms. These include high fever, persistent cough, wheezing, difficulty breathing, and episodes of stopped breathing (apnea). Older children and adults usually experience much milder symptoms. Health Canada provides updated guidance on RSV prevention and care.
Ear Infections in Children
Ear infections are among the most common childhood illnesses seen by Canadian family doctors. Young children are especially prone to them because their Eustachian tubes — the small passages connecting the throat to the ears — are shorter and more horizontal than in adults.
When a cold causes inflammation, these tubes can become blocked. Fluid then builds up behind the eardrum, creating a warm environment where germs can grow quickly.
Signs Your Child Has an Ear Infection
Watch for fever, unusual fussiness, and your child tugging or pulling at their ear. These are classic signs that something is wrong. However, not all ear infections cause obvious pain, especially in very young babies.
The good news is that most ear infections are caused by viruses and clear up on their own. Childhood vaccinations also help prevent certain bacterial infections that can lead to ear trouble. Ask your child’s doctor about keeping immunizations up to date.
Otitis Media With Effusion (Glue Ear)
Sometimes fluid stays in the middle ear even after an infection is gone. This is called otitis media with effusion, or “glue ear.” It can happen after an acute ear infection or an upper respiratory illness.
In many cases, the fluid drains on its own within a few weeks. However, if it lingers or becomes thick and sticky, it can affect your child’s hearing. In those situations, a doctor may recommend small drainage tubes to help clear the fluid.
Croup, Hand-Foot-and-Mouth Disease, and Fifth Disease
Croup
Croup is easy to recognize once you have heard it. The defining symptom is a harsh, barking cough — many parents describe it as sounding like a seal. This is one of the most common childhood illnesses in children under five years old in Canada.
The barking sound comes from inflammation in the upper airways, usually caused by a virus. Most children recover within about a week at home. However, if breathing becomes severely difficult, your child may need treatment at a hospital. Steam or cool night air can sometimes provide short-term relief — but always follow your doctor’s advice.
Hand-Foot-and-Mouth Disease
Despite its alarming name, hand-foot-and-mouth disease is usually mild. It causes fever along with small blisters or sores inside the mouth, on the palms of the hands, the buttocks, and the soles of the feet. The coxsackievirus A16 causes most cases.
This illness tends to spread among children during the summer and early fall. Most cases resolve on their own within seven to ten days. Keep your child home from school or daycare while they are symptomatic to prevent spreading it to others.
Fifth Disease (Slapped Cheek Disease)
Fifth disease gets its nickname — “slapped cheek disease” — from the bright red rash it causes on a child’s face. The rash can also spread to the trunk, arms, and legs. Human parvovirus B19 is responsible for this common childhood illness.
Before the rash appears, a child may have cold-like symptoms such as a mild fever and runny nose. Once the rash shows up, the child is no longer contagious. Up to 20% of five-year-olds and around 60% of children under 19 will experience fifth disease at some point. The rash usually fades within seven to ten days.
Pink Eye and Rotavirus
Conjunctivitis (Pink Eye)
Pink eye is one of the most contagious common childhood illnesses. It causes redness, tearing, itching, and crusty discharge around the eyes. It spreads quickly through schools and daycares, particularly in the fall and winter months.
There are three main types of pink eye:
Bacterial conjunctivitis: Caused by direct contact with infected discharge or contaminated surfaces. The eye often has thick yellow, white, or green discharge. It is very contagious and may require antibiotic eye drops.
Viral conjunctivitis: Triggered by the same viruses that cause the common cold. It produces watery or slightly thick discharge. Children may also feel a burning or gritty sensation and sensitivity to light. This type is also highly contagious.
Allergic conjunctivitis: Caused by allergens like pollen or pet dander. Symptoms include itching, swelling, tearing, and redness. This type is not contagious.
See your child’s doctor or visit a walk-in clinic to find out which type your child has. Treatment depends on the cause. Most cases of pink eye resolve within seven to ten days. The Mayo Clinic offers helpful information on pink eye causes and treatment.
Rotavirus
Before an effective vaccine became available, rotavirus was the leading cause of severe diarrhea and dehydration-related death in young children worldwide. Today, two safe vaccines are available for infants in Canada, and they have dramatically reduced the number of cases.
Rotavirus causes vomiting and watery diarrhea that can dehydrate a child very quickly. If your infant or toddler develops these symptoms, contact your doctor promptly. Keeping your child hydrated is the most important step while they recover.
Kawasaki Disease: A Rare but Serious Condition
Kawasaki disease is rare and not fully understood, but it is one of the common childhood illnesses that parents should know about. It mainly affects children under five years old. Without treatment, it can cause problems with the heart’s blood vessels.
Symptoms include prolonged high fever (lasting more than five days), a rash, redness of the eyes, swollen lymph nodes in the neck, and changes to the lips or tongue — sometimes called “strawberry tongue.” The hands and feet may also become red and swollen.
If you notice these symptoms together, seek medical care right away. Early treatment with medication significantly reduces the risk of heart complications. The World Health Organization provides global health guidance on infectious and inflammatory conditions in children.
When to See a Doctor
Many common childhood illnesses will resolve on their own with rest and fluids at home. However, some symptoms need prompt medical attention. Visit your family doctor, a walk-in clinic, or an emergency room if your child has any of the following:
Difficulty breathing or very fast breathing
A high fever that does not come down with medication
Signs of dehydration — dry mouth, no tears, no wet diapers for hours
Extreme drowsiness or difficulty waking up
A rash combined with fever and stiff neck
Symptoms that are getting significantly worse after a few days
Any symptom that worries you as a parent
Most provincial health plans in Canada cover visits to family doctors and walk-in clinics. If you do not have a family doctor, a walk-in clinic can assess your child and refer you if needed. Trust your instincts — you know your child best.
What are the most common childhood illnesses in Canada?
The most common childhood illnesses in Canada include ear infections, RSV, croup, hand-foot-and-mouth disease, pink eye (conjunctivitis), and fifth disease. Most of these spread easily in schools and daycares, especially during the fall and winter months. Keeping vaccinations up to date helps prevent several of these conditions.
How do I know if my child’s illness needs a doctor’s visit?
See a doctor if your child has trouble breathing, a very high fever, signs of dehydration, or symptoms that are getting worse instead of better. For common childhood illnesses that are mild, rest and fluids at home are often enough. When in doubt, call your family doctor or visit a walk-in clinic — it is always better to check.
Is RSV dangerous for babies?
RSV can be serious for babies and children under two or three years old, sometimes causing wheezing, breathing difficulties, or a need for hospital care. However, most children with RSV recover at home with rest and fluids. Contact your doctor right away if your baby shows signs of laboured breathing or stops eating and drinking normally.
Can pink eye clear up on its own without treatment?
Viral and allergic conjunctivitis often clear up on their own within seven to ten days without prescription treatment. Bacterial pink eye, however, may need antibiotic eye drops to heal properly and prevent spreading. A family doctor or walk-in clinic can determine which type your child has and recommend the right treatment.
What vaccines help prevent common childhood illnesses?
Several vaccines on Canada’s routine immunisation schedule protect against common childhood illnesses, including rotavirus, certain bacterial strains that cause ear infections, and more. RSV vaccines for high-risk infants are also becoming available. Talk to your child’s doctor about which vaccines are recommended and covered under your provincial health plan.
How long does hand-foot-and-mouth disease last in children?
Hand-foot-and-mouth disease is one of the common childhood illnesses that usually resolves within seven to ten days. The fever typically appears first, followed by blisters in the mouth and on the hands, feet, and buttocks. Keep your child home during this time to avoid spreading the virus to other children.
Key Takeaways
Common childhood illnesses range from mild infections like pink eye and fifth disease to more serious conditions like RSV and Kawasaki disease.
Most illnesses — including croup, hand-foot-and-mouth disease, and viral pink eye — clear up on their own within one to two weeks.
RSV is the leading cause of serious respiratory illness in children under two. Watch for breathing difficulties and contact your doctor promptly.
Ear infections are very common in young children. Most are caused by viruses and resolve without antibiotics.
Keeping your child’s vaccinations up to date is one of the best ways to prevent several childhood illnesses.
If you are ever unsure about your child’s symptoms, your family doctor or a local walk-in clinic is the right first call. Your provincial health plan covers most visits.
This article is for general information only and is not a substitute for professional medical advice. Always consult your family doctor or a qualified healthcare provider for diagnosis and treatment of your child’s health concerns.
