Common illnesses in babies 

Common illnesses in babies

Whilst your baby is growing, so is their immune system. As this is developing, it is easier for them to get sick. In this article we are going to cover the most common illnesses in babies and their symptoms. 

Respiratory Syncytial Virus (RSV)

A respiratory syncytial virus is a viral infection that affects the airways. RSV is one of the most common illnesses in babies and is actually the most common respiratory infection causing hospitalization in young babies. 

This isn’t usually a serious illness, but if your child is under two or has any existing lung or heart conditions or weak immune system, RSV can inflame the lungs which can lead to pneumonia. 


Its symptoms are very much like a cold, such as a runny nose and cough. It can also cause irritable breathing problems. 

Fifth Disease

Another one of the more common viral illnesses in babies, Fifth Disease is most common in children aged five to fifteen. Fifth disease is also not usually a serious illness, but if your child has sickle cell anemia or a weak immune system they can be highly affected by Fifth Disease. This can also be very serious in pregnant women as it can seriously harm the baby whilst it is still growing. 


The beginning symptoms of Fifth Disease tend to be a very low fever, a runny nose, and cough which can seem like a cold and swollen joints, during the early stages, your child will be contagious, so it’s good to keep them separated from other children.

 If the cold symptoms persist after a few days you would start to notice a bright red rash, usually on the face which would spread onto the body. Something to note, once the rash appears, your child is no longer contagious.
It can take 1 to 3 weeks for the rash to go away. In some children, the rash may itch, and the joints may ache. Your doctor can recommend ways to ease these symptoms.

Hand, Foot, and Mouth Disease

This is another contagious viral illness that is usually not serious but can have some uncomfortable symptoms. It’s most common among children under the age of five as it is most commonly spread through saliva. Outbreaks are very common if one child contracts it and they interact with a lot of other children, such as in a daycare or nursery. 


The early symptoms of Hand, Foot, and Mouth Disease are not very serious, they are usually a slight fever, sore throat, and a loss in appetite. After a few days they will get to the more uncomfortable symptoms which can include painful sores in the back of the throat, skin rashes which usually occur on the palm and sole of the foot. All of these symptoms do clear up after around seven days without any treatment.  


Croup is most common in the fall and early winter when the weather is cold and dry. It’s more common in boys between three months and five years of age. Croup targets the upper throat, windpipe, and voice box. Croup is contagious, especially in the first few days or until your child’s fever is gone, but luckily it only lasts for a week or so.


Croup usually starts with a sudden onset of a barky cough, which gets worse at night. They will also have a runny nose and slight fever. To relieve the barky cough, you can set up a mist humidifier near your child’s bed to use whilst they are sleeping. If you don’t have a humidifier, set your shower to hot and sit in the bathroom with your child for ten minutes before they go to bed.

Scarlet Fever

Scarlet Fever is a bacterial infection, caused by group A streptococcus, which is a bacteria carried in the throat. It was once a deadly disease, but now it’s easily treatable.


The symptoms of Scarlet Fever include a sore throat, but most commonly and what gives it its name, you will notice a scarlet-colored rash around the neck and face area that can spread to the rest of the body.


Impetigo is a skin infection that is most common in younger children. It can start when staph or strep bacteria get into a cut, scratch, or open wound. I can affect any part of your child’s body, but most commonly around the mouth, nose, and hands. In babies still wearing diapers, it can occur around the diaper area. 


The most common symptoms are tiny blisters that burst, the fluid from the sores creates a crust that looks like a coat of honey. If you notice your baby itching or touching the sores, you will need to stop this as this can spread the infection to other parts of the body and also other people. 

Kawasaki Disease

This disease causes the blood vessels to inflame throughout the body. Kawasaki Disease is very rare, and most commonly occurs in boys under the age of five. Most babies and children will recover from this in a few weeks, but if it affects the arteries near the heart it can cause some serious long term issues. 


The symptoms usually consist of a fever that lasts five days, or more. You would also notice red eyes, red lips, and redness on the hands or feet. In some cases you could also notice a rash and swollen lymph nodes. There is no way to prevent this disease, but it is not contagious. The key to Kawasaki Disease is to treat it as early as possible.

Reye’s Syndrome

Reye’s Syndrome is a very rare illness that can come on suddenly. Young children who are getting over a viral illness such as chickenpox or the flu are most likely to get it. Reye’s Syndrome can be serious and cause damage to the liver and brain if not treated quickly.


The most common early symptoms of Reye’s Syndrome include vomiting, general lack of energy, and irritability. After this, you can notice irrational behavior, confusion, and in rare cases seizures. If you suspect your child has it, get medical help right away.

Whooping Cough (Pertussis)

Anyone can catch Whooping Cough which is a bacterial infection of the lungs and breathing tubes, but infants are the most likely to get seriously ill from it. Whooping Cough is highly contagious and most commonly spreads very quickly around daycare centers and schools.


The most common symptoms are very much like the common cold symptoms. But after a few days the cough will get worse and a whooping sound may be heard when your child gasps for air. The easiest way to prevent this is to make sure your child gets vaccinated early.

We hope this article will help with any questions about common illnesses in babies. But of course, if your baby gets ill, its always best to consult a doctor. We hope you and your baby stay safe and healthy. 

Please follow and like us: