Reye's Syndrome Blood Test

What is Reye's Syndrome?

Reye's syndrome is a rare but serious condition that causes swelling in the liver and brain, primarily affecting children and teenagers. It is caused by mitochondrial dysfunction in liver cells, often triggered by aspirin use during viral infections like influenza or chickenpox. The Ammonia Plasma test is the most important test for monitoring Reye's syndrome because elevated ammonia levels indicate liver damage severity and brain toxicity risk.

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What causes Reye's syndrome?

Reye's syndrome is caused by mitochondrial dysfunction in liver cells that disrupts normal metabolism and leads to toxic ammonia buildup. The condition is most commonly triggered by giving aspirin to children or teenagers during viral infections like influenza, chickenpox, or other respiratory illnesses. When mitochondria fail to function properly, the liver cannot process ammonia and other toxins, causing them to accumulate in the bloodstream and reach dangerous levels that affect the brain, leading to swelling and potentially life-threatening neurological complications.

What is the best test for Reye's syndrome?

The Ammonia Plasma test is the most important test for Reye's syndrome because it measures ammonia levels in the blood, which become significantly elevated when the liver is damaged and cannot process toxins properly. High ammonia concentrations are toxic to the brain and directly contribute to the dangerous neurological symptoms like confusion, seizures, and loss of consciousness seen in this condition. While Reye's syndrome is diagnosed clinically based on symptoms and medical history, monitoring ammonia levels is essential for assessing disease severity, guiding emergency treatment decisions, and tracking patient response to therapy in the hospital setting.

When should I get tested for Reye's syndrome?

You should get tested immediately if a child or teenager who recently had a viral infection like flu or chickenpox suddenly develops persistent vomiting, unusual drowsiness, confusion, aggressive behavior, or seizures, especially if they took aspirin during the illness. Reye's syndrome is a medical emergency that requires immediate hospitalization and testing. Early symptoms can rapidly progress from lethargy and vomiting to severe brain swelling, coma, and life-threatening complications within hours, so urgent medical evaluation and blood work to check ammonia and liver function are critical for survival and preventing permanent brain damage.

What are the symptoms of Reye's syndrome?
Reye's syndrome symptoms typically appear in two stages, starting with persistent vomiting and extreme tiredness about 3-5 days after a viral illness begins to improve. As the condition progresses, neurological symptoms develop including irritability, aggressive behavior, confusion, seizures, loss of consciousness, and in severe cases, coma. In infants, symptoms may include diarrhea, rapid breathing, and unusual sleepiness rather than vomiting. The condition can deteriorate rapidly from mild symptoms to severe brain swelling within hours, making immediate medical attention essential when symptoms appear.
Who is at risk for Reye's syndrome?
Children and teenagers between ages 4 and 14 are at highest risk for Reye's syndrome, particularly those who take aspirin or aspirin-containing medications during viral infections like influenza, chickenpox, or upper respiratory infections. The risk is dramatically increased when aspirin is given during these illnesses, which is why aspirin use is not recommended for anyone under 18 years old unless specifically prescribed for certain conditions. Children with underlying metabolic disorders affecting fatty acid oxidation are also at increased risk. Since the widespread warning against giving aspirin to children, Reye's syndrome has become extremely rare, with fewer than 20 cases reported annually in the United States.
What happens if Reye's syndrome is left untreated?
Untreated Reye's syndrome can rapidly progress to severe brain swelling, seizures, respiratory failure, coma, and death within days or even hours of symptom onset. The toxic buildup of ammonia and other metabolic waste products causes increasing pressure inside the skull, which can lead to permanent brain damage, intellectual disabilities, muscle weakness, and vision or speech problems in survivors. The mortality rate for Reye's syndrome can be as high as 40% without prompt medical intervention, and many survivors experience long-term neurological complications. Immediate hospitalization with intensive care monitoring and treatment to reduce brain swelling and control ammonia levels is essential for survival and minimizing permanent damage.
Can Reye's syndrome be diagnosed with a blood test?
Reye's syndrome cannot be diagnosed with a single blood test alone, but blood work is critical for confirming the diagnosis and monitoring the condition. The Ammonia Plasma test shows elevated ammonia levels, while liver function tests reveal abnormal liver enzymes without jaundice, which are characteristic findings in Reye's syndrome. Blood tests also check blood sugar levels, which are often low, and measure clotting factors that may be impaired due to liver dysfunction. These blood test results, combined with clinical symptoms, recent viral illness history, and aspirin use, help doctors confirm the diagnosis and rule out other conditions with similar symptoms.
How is Reye's syndrome treated?
Reye's syndrome treatment focuses on intensive supportive care in a hospital setting to reduce brain swelling, control ammonia levels, and maintain vital functions while the liver recovers. Doctors administer intravenous fluids to maintain hydration and electrolyte balance, medications to reduce brain swelling and intracranial pressure, and glucose to correct low blood sugar. Mechanical ventilation may be necessary to ensure adequate breathing, and in severe cases, dialysis can help remove excess ammonia from the blood. Close monitoring in an intensive care unit is essential, with frequent blood tests to track ammonia levels, liver function, and other metabolic parameters until the acute crisis resolves and the liver begins to heal.
How can I prevent Reye's syndrome?
The most important prevention strategy is never giving aspirin or aspirin-containing medications to children or teenagers under 18 years old who have viral infections like flu, chickenpox, or colds. Always check medication labels carefully, as aspirin may be listed as acetylsalicylic acid, salicylate, or found in combination products like Pepto-Bismol. Use acetaminophen or ibuprofen instead for fever and pain relief in children. Additionally, getting the annual flu vaccine and chickenpox vaccine reduces the risk of viral infections that can trigger Reye's syndrome. If your child has been prescribed aspirin for a specific medical condition like Kawasaki disease, talk to your doctor about alternative options during flu season.
What can I do at home for Reye's syndrome?
Reye's syndrome is a medical emergency that cannot be treated at home and requires immediate hospitalization in an intensive care unit. If you suspect Reye's syndrome, call 911 or go to the emergency room immediately rather than attempting home care. The condition progresses rapidly and requires specialized medical interventions including intravenous medications, brain pressure monitoring, and potentially mechanical ventilation that are only available in a hospital setting. There are no home remedies or natural treatments that can address the life-threatening liver dysfunction and brain swelling caused by Reye's syndrome. Every minute counts in getting emergency medical care to prevent permanent brain damage or death.
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