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Children - Contagious childhood diseases (Part II)

Published on October 21, 2014 at 14:41 / Updated on July 22, 2019 at 18:22

Parents often wonder whether it is necessary to keep their children at home when they are sick –how long are they contagious, and should they stay home? The answer varies depending on the disease.


Definition, symptoms and causal agents 

Chickenpox is caused by the varicella zoster virus. It is a very contagious but usually benign disease characterized by a skin rash accompanied by sometimes severe itching.

Infected individuals may have blisters over their whole body. These blisters usually appear in the two weeks following contact with an infected individual. These little red blisters, which are filled with liquid, eventually burst and form a crust.

Other symptoms may include fever, stomach aches, loss of appetite, discomfort or irritability. Cold-like symptoms sometimes precede the onset of the blisters.


Chickenpox is very contagious and is usually transmitted through direct contact with the skin of an infected individual, or though contaminated droplets that are dispersed in the air when the infected person coughs or sneezes.

Treatment Giving children warm baths containing baking soda or oatmeal can help relieve the itching and momentarily distract them. You can also apply calamine lotion to the blisters. If the itching is severe, your doctor may prescribe an antihistamine.

Acetaminophen or ibuprofen can be administered in cases where infected children have a fever or complain of pain.

Going back to school? Children with chickenpox are no longer quarantined. They can go back to school once they feel well enough, even if they still have blisters.


There is a vaccine against chickenpox. Since January 2006, it has been part of the free immunization schedule recommended by the Ministère de la santé et des services sociaux du Québec. It requires only one injection, which is given after the age of 12 months.

IMPETIGO Definition, symptoms and causal agents 

Impetigo is a skin infection caused by bacteria that take advantage of a superficial wound (e.g. scratch, insect bite) to enter the skin and multiply. The wound becomes covered with blisters filled with liquid and surrounded by a red border. When the blisters burst, a liquid is released and a yellowish or greyish crust forms.


Impetigo is very contagious. It is transmitted through direct contact, usually when infected individuals touch their blisters and then touch another person. Infected persons can also spread the infection to other parts of their body if they touch the wound and then scratch another spot. It is therefore extremely important for infected individuals to wash their hands often, especially if they’ve touched their wound.


The doctor may prescribe an antibiotic (cream or tablets) to treat impetigo.

Going back to school? The antibiotic treatment usually cures the infection in five days, but the child can go back to school 24 hours after the beginning of the antibiotic treatment.


There is no vaccine against impetigo.

OTITIS - Definition, symptoms and causal agents 

Otitis is one of the most common childhood diseases. It is estimated that three out of four children have already had one episode of otitis before the age of three. Most children stop getting these infections when they reach the age of four or five.

Otitis usually begins with a viral infection such as a cold. It can also be caused by a blockage or inflammation of the eustachian tube, a narrow passageway that connects the inner ear to the nose. When liquid gets trapped in the middle ear during a cold, this causes the characteristic pain and infection of otitis.

Children suffering from otitis complain of pain in the affected ear, are particularly irritable, may have difficulty sleeping and may have a fever.


The microbes responsible for otitis are spread in the same way as those of the cold and flu: through droplets in the air and contaminated hands that touch the mucous membranes of the face.


Most cases of otitis are resolved without intervention. When a child is older than six months of age and presents no serious symptoms (pain, fever), it is reasonable to wait 48 hours before consulting a physician. If the infection is caused by a virus, you should note a gradual improvement in your child’s symptoms. If they are still significant after that period, it is advisable to see a physician.

You can alleviate the pain and fever with acetaminophen or ibuprofen. Applying warm and humid compresses to the affected ear may also help ease the pain.

If you saw a physician and antibiotics were prescribed, it is important to take them all, even if the symptoms disappear before the end of the treatment.

Going back to school? Children can go back to school if they have no fever and feel well enough to take part in school activities.


There is no specific vaccine to prevent otitis.

FIFTH DISEASE (ERYTHEMA INFECTIOSUM) AND HAND, FOOT AND MOUTH DISEASE (HFMD) - Definition, symptoms and causal agents These two diseases are caused by viruses and are usually benign.

Fifth disease (erythema infectiosum) is characterized by the appearance of bright redness on the face (as if the child had been slapped), followed by a red, lacy skin rash all over the body, which can last for several weeks. It is sometimes accompanied by fever, muscle or throat pain, or fatigue. Pregnant women who come into contact with someone who is infected with fifth disease should see a physician; if they contract the disease during pregnancy, there is a small risk that their baby could develop anemia before birth.

Hand, foot and mouth disease (HFMD) is caused by a virus that predominantly affects children under the age of ten. It is characterized by fever, followed a few days later by the onset of painful reddish spots in the mouth. The child may also complain of a sore throat. Afterwards, a skin rash usually develops on the palm of the hands and under the feet, and sometimes on the buttocks as well. These spots sometimes develop into blisters.


Fifth disease and HFMD are transmitted through contact with contaminated droplets that are scattered in the air when an infected person coughs or sneezes, or through direct contact with the skin lesions.


There is no treatment to cure these two viral infections. They must run their course. However, you can give your child acetaminophen or ibuprofen to relieve the fever and pain, when necessary.

In cases where children have painful lesions to the mouth, it is recommended that you feed them soft, cold foods such as compote, pudding or ice cream.

Going back to school? Children with fifth disease can go back to school once they feel well enough to return to their activities, even if they still have a skin rash on their body. In fact, once the skin rash appears, the child is no longer contagious.

When children with HFMD have painful mouth lesions, they should remain home until those sores have healed and they can eat normally. Some children get blisters under their feet, and this makes wearing shoes uncomfortable. It is recommended that they remain home until these blisters are healed.


There is no vaccine against these two diseases.

In a nutshell 

When children have a fever or are in pain, acetaminophen and ibuprofen are usually a good choice. Remember, however, that you must never give aspirin to a child, since this medication has been associated with a rare but serious adverse effect called Reye's syndrome.

Since their immune system is still developing and they are spending so much time in groups, children are more prone to catching various contagious diseases. However, most of these diseases are fairly benign and resolve on their own.

As the old saying goes, “an ounce of prevention is worth a pound of cure.” Three simple measures can make a huge difference when it comes to transmitting contagious diseases: 1) washing our hand often, 2) covering our mouth or nose when coughing or sneezing, and 3) getting our children vaccinated.

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