In Reye's syndrome, a child's blood sugar level typically drops while the levels of ammonia and acidity in his or her blood rise. At the same time, the liver may swell and develop fatty deposits. Swelling may also occur in the brain, which can cause seizures, convulsions or loss of consciousness.
The signs and symptoms of Reye's syndrome typically appear about three to five days after the onset of a viral infection, such as the flu (influenza) or chickenpox, or an upper respiratory infection, such as a cold.
Initial signs and symptoms
For children younger than age 2, the first signs of Reye's syndrome may include:
For older children and teenagers, early signs and symptoms may include:
- Persistent or continuous vomiting
- Unusual sleepiness or lethargy
Additional signs and symptoms
As the condition progresses, signs and symptoms may become more serious, including:
- Irritable, aggressive or irrational behavior
- Confusion, disorientation or hallucinations
- Weakness or paralysis in the arms and legs
- Excessive lethargy
- Decreased level of consciousness
These signs and symptoms require emergency treatment.
When to see a doctor
Early diagnosis and treatment of Reye's syndrome can save a child's life. If you suspect that your child has Reye's syndrome, it's important to act quickly.
Seek emergency medical help if your child:
- Has seizures or convulsions
- Loses consciousness
Contact your child's doctor if your child experiences the following after a bout with the flu or chickenpox:
- Vomits repeatedly
- Becomes unusually sleepy or lethargic
- Has sudden behavior changes
The exact cause of Reye's syndrome is unknown, although several factors may play a role in its development. Reye's syndrome seems to be triggered by using aspirin to treat a viral illness or infection — particularly flu (influenza) and chickenpox — in children and teenagers who have an underlying fatty acid oxidation disorder.
Fatty acid oxidation disorders are a group of inherited metabolic disorders in which the body is unable to break down fatty acids because an enzyme is missing or not working properly. A screening test is needed to determine if your child has a fatty acid oxidation disorder.
In some cases, Reye's syndrome may be an underlying metabolic condition that's unmasked by a viral illness. Exposure to certain toxins — such as insecticides, herbicides and paint thinner — also may contribute to Reye's syndrome.
The following factors — usually when they occur together — may increase your child's risk of developing Reye's syndrome:
- Using aspirin to treat a viral infection, such as flu, chickenpox or an upper respiratory infection
- Having an underlying fatty acid oxidation disorder
Most children and teenagers who have Reye's syndrome survive, although varying degrees of permanent brain damage are possible. Without proper diagnosis and treatment, Reye's syndrome can be fatal within a few days.
Use caution when giving aspirin to children or teenagers. Though aspirin is approved for use in children older than age 2, children and teenagers recovering from chickenpox or flu-like symptoms should never take aspirin. This includes plain aspirin and medications that contain aspirin.
Some hospitals and medical facilities conduct newborn screenings for fatty acid oxidation disorders to determine which children are at greater risk of developing Reye's syndrome. Children with known fatty acid oxidation disorders should not take aspirin or aspirin-containing products.
Always check the label before you give your child medication, including over-the-counter products and alternative or herbal remedies. Aspirin can show up in some unexpected places, such as Alka-Seltzer.
Sometimes aspirin goes by other names, too, such as:
- Acetylsalicylic acid
- Salicylic acid
If your child has the flu, chickenpox or another viral illness, use other medications — such as acetaminophen (Tylenol, others), ibuprofen (Advil, Children's Motrin, Motrin IB, others) or naproxen (Aleve) — to reduce high fever or relieve pain.
There's one caveat to the aspirin rule, however. Children and teenagers who have certain chronic diseases, such as Kawasaki disease, may need long-term treatment with drugs that contain aspirin.
If your child needs aspirin therapy, make sure his or her vaccines are current — including two doses of the varicella (chickenpox) vaccine and a yearly flu vaccine. Avoiding these two viral illnesses can help prevent Reye's syndrome.