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Pertussis (Whooping Cough): When to Go to Emergency

Healthcare provider preparing to give baby a shot.
Vaccination helps protect your child from pertussis.
Pertussis (also known as whooping cough) is a highly contagious infection of the respiratory tract. It spreads through droplets when an infected person coughs or sneezes. Because pertussis can be very serious, it’s important to know when to seek medical care.

Risk Factors

Babies and preschool-age children are most at risk. At age 2 months, most infants in the United States start the vaccination series to prevent pertussis. But the effects of the vaccine fade as children get older, so teens and adults can also get the disease.

When to go to the emergency department (ED)

At first, pertussis may seem like a cold. Your child is likely to have a runny nose, mild fever, and a slight cough. After 1 to 2 weeks, the cough tends to become very severe. Coughing spells may last as long as a minute. These produce a “whooping” sound as your child gasps for air. Sometimes, your child may turn red or blue or vomit from the cough. Call your healthcare provider right away if you suspect pertussis. Seek emergency help if your child:

  • Has a blue color to his or her skin (check fingertips and around mouth). (If there is a blue color, call 911.)

  • Stops breathing, even for an instant. (Call 911.)

  • Has a fever (see Fever and children, below.

  • Vomits often, or becomes dehydrated

Fever and children

Always use a digital thermometer to check your child’s temperature. Never use a mercury thermometer.

For infants and toddlers, be sure to use a rectal thermometer correctly. A rectal thermometer may accidentally poke a hole in (perforate) the rectum. It may also pass on germs from the stool. Always follow the product maker’s directions for proper use. If you don’t feel comfortable taking a rectal temperature, use another method. When you talk to your child’s healthcare provider, tell him or her which method you used to take your child’s temperature.

Here are guidelines for fever temperature. Ear temperatures aren’t accurate before 6 months of age. Don’t take an oral temperature until your child is at least 4 years old.

Infant under 3 months old:

  • Ask your child’s healthcare provider how you should take the temperature.

  • Rectal or forehead (temporal artery) temperature of 100.4°F (38°C) or higher, or as directed by the provider

  • Armpit temperature of 99°F (37.2°C) or higher, or as directed by the provider

Child age 3 to 36 months:

  • Rectal, forehead (temporal artery), or ear temperature of 102°F (38.9°C) or higher, or as directed by the provider

  • Armpit temperature of 101°F (38.3°C) or higher, or as directed by the provider

Child of any age:

  • Repeated temperature of 104°F (40°C) or higher, or as directed by the provider

  • Fever that lasts more than 24 hours in a child under 2 years old. Or a fever that lasts for 3 days in a child 2 years or older.

What to expect in the ED

A healthcare provider will ask about your child’s symptoms and perform a physical exam. He or she will likely take samples of secretions from your child’s nose or throat. These will be checked in a lab for the bacteria that cause pertussis. Your child also may have blood tests or X-rays.


Infants and children with severe pertussis are likely to be admitted to the hospital for treatment with antibiotics and fluids. Milder cases may be treated at home with antibiotics, fluids, and bed rest. Cough and cold medicines are not very helpful. Because of the possibility of serious side effects, they should not be used in children younger than age 4 years. These medicines should be used only in children between ages 4 and 6 years, if your healthcare provider recommends them. Never give aspirin to a child under age 18 years. It could cause a rare but serious condition called Reye's syndrome. Generally, ibuprofen is not recommended for infants younger than age 6 months.


Getting vaccinated is the best way to protect against pertussis. Talk to your healthcare provider about whether your child needs a booster vaccination. Also, be sure to ask whether you need a booster as well.

© 2000-2017 The StayWell Company, LLC. 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.