Human parainfluenza viruses (HPIVs) are a group of viruses that cause respiratory infections. They can occur at any age but are more common in babies and young children. They are more likely to occur in people with a weak immune system.

Most HPIVs infect the upper airway, meaning the nose and throat. This results in symptoms that include nasal congestion, ear infections, or sore throat. Other HPIVs infect the lower respiratory tract. They can result in pneumonia, bronchiolitis, or croup. Croup outbreaks often occur during the fall and winter, but they can occur at any time of the year.

HPIVs can be spread by coming in contact with droplets from an infected person's nose or mouth. A child may breathe in droplets or touch their eyes, nose, or mouth with a contaminated hand. Most children have an infection with HPIV before they are 5 years old. They may then have occasional reinfection when they are older. But these infections are often less severe.

Children between ages 3 months and 5 years old are most likely to get croup. Children younger than age 2 are more likely to get lower respiratory tract infections, such as pneumonia or bronchiolitis. Reinfections can occur after the first infection. But they are often less severe.

Symptoms may be a bit different for each child. They can include:

• A runny nose.
• Eye redness or swelling.
• A cough that sounds like a barking seal.
• Noisy, harsh breathing.
• A hoarse voice when speaking or crying.
• Rattling felt on the chest or back when breathing.
• A high-pitched sound when breathing (wheezing), which is more common with asthma.
• Noisy breathing (stridor), which is more common with bronchiolitis.
• Fever.
• Irritability.
• Loss of appetite.
• Vomiting.
• Diarrhea.

The symptoms of HPIVs can seem like other health conditions. Take your child to their doctor for a diagnosis.

The doctor will ask about your child's symptoms and health history. They may also ask about your family's health history. The doctor will give your child a physical exam. Your child may also have tests, such as:

• A blood test.
• A nasal swab of respiratory secretions.
• A chest X-ray.

Treatment will depend on your child's symptoms, age, and general health. It will also depend on how severe the condition is. Antibiotics are not used to treat this illness. The goal of treatment is to help reduce symptoms until the infection goes away.

Croup symptoms can be scary for parents. Supportive treatment for croup may include:

• Taking your child into cool, night air.
• Having your child sit in a steamy bathroom with the shower running to ease breathing.
• Having your child drink plenty of fluids.
• Treating a fever with acetaminophen or ibuprofen, if your child's doctor says it's okay.
• Keeping your child as quiet and calm as possible to help reduce their breathing effort.

Talk with your child's doctor about the risks, benefits, and possible side effects of all medicines.

Don't give ibuprofen to a child younger than 6 months old, unless your doctor tells you to.

Don't give aspirin (or medicine that contains aspirin) to a child younger than 19 years, unless directed by your child's doctor. Taking aspirin can put your child at risk for Reye syndrome. This is a rare but very serious disorder that often affects the brain and the liver.

A child with a weak immune system may get life-threatening pneumonia.

There is currently no vaccine or antiviral medicine to treat HPIV. Frequent handwashing with soap and clean, running water is important to prevent the spread of HPIVs to other babies and children. If your child is in the hospital, health care workers may wear masks, gowns, and gloves when they enter your child's room to prevent the spread to others.

Contact the doctor if your child has:

• Symptoms that don't get better, or get worse.
• New symptoms.

• Human parainfluenza viruses (HPIVs) are a group of viruses that cause different types of respiratory infections.
• Most HPIVs often cause upper airway infections. These include the common cold, ear infections, or sore throat.
• Other infections caused by HPIVs affect the lower respiratory tract. These include pneumonia, bronchiolitis, and croup.
• Children between ages 3 months and 5 years old are most likely to get croup. Children younger than age 2 are more likely to get lower respiratory tract infections, such as pneumonia or bronchiolitis.
• Antibiotics are not used to treat HPIVs. The goal of treatment is to help reduce symptoms until the infection goes away.
• Frequent handwashing with soap and clean, running water is important to prevent the spread of HPIVs to other babies and children.

Tips to help you get the most from a visit to your child's doctor:

• Know the reason for the visit and what you want to happen.
• Before your visit, write down questions you want answered.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you for your child.
• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are and when they should be reported.
• Ask if your child's condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if your child does not take the medicine or have the test or procedure.
• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your child's doctor after office hours, and on weekends and holidays. This is important if your child becomes ill and you have questions or need advice.