Brief overview
- Symptoms: vomiting and nausea, confusion, restlessness, irritability, drowsiness; seizures up to coma
- Causes: Unclear, viral infections probably play a role
- Risk factors: Drugs such as acetylsalicylic acid probably favor the development
- Diagnosis: Medical history, typical symptoms, physical examination, altered laboratory values
- Treatment: Alleviation of symptoms, ensuring the child’s survival, especially treatment of cerebral edema, support of liver function
- Course and prognosis: Frequently severe course, often neurological damage remains; around 50 percent of those affected die
- Prevention: Do not use acetylsalicylic acid in children under the age of 15, or only with particular caution
What is Reye’s syndrome?
Reye’s syndrome is a rare, severe and potentially life-threatening disease of the brain and liver (“hepatic encephalopathy”). It usually affects children from the age of five and adolescents up to the age of 15. It occurs particularly frequently after a viral infection and the intake of acetylsalicylic acid (ASA). The exact connection is still unclear.
Reye’s syndrome was discovered in Australia in the 1970s. Shortly afterwards, doctors in America linked many cases of severe liver and brain diseases to Reye’s syndrome. However, it took a few more years before the first suspicions about a connection with viral diseases and the painkiller and antipyretic acetylsalicylic acid emerged.
The result was widespread publicity in the media that acetylsalicylic acid should not be administered to children. Although Reye’s syndrome has actually occurred far less frequently since then, the connection between the virus, ASA and Reye’s syndrome has never been clearly established.
Symptoms
Reye’s syndrome often occurs in children when parents actually think that the viral infection has been overcome. In some cases, it takes up to three weeks after recovery before the symptoms of Reye’s syndrome appear. Initially, there is increased vomiting without nausea. Affected children appear lethargic and are listless and sleepy.
As the disease progresses, the children often barely react to speech and other environmental stimuli (stupor). They are disoriented and may appear irritable, restless and confused. Pulse and respiratory rate are often increased. Some children with Reye’s syndrome suffer a seizure or fall into a coma, and some stop breathing.
Reye’s syndrome also leads to damage and fatty degeneration of the liver. Its function is severely restricted, which leads to a variety of metabolic disorders with different symptoms. In addition to the neurotoxin ammonia, increased bilirubin enters the blood, which can lead to a yellow skin color.
In general, the child appears seriously ill and requires urgent intensive medical care.
Causes and risk factors
The exact causes of Reye’s syndrome are not known. However, experts do know that Reye’s syndrome is caused by damage to the mitochondria. Mitochondria are often referred to as the power plants of cells because they are essential for energy production. The malfunction of the mitochondria in Reye’s syndrome is particularly evident in the cells of the liver and brain, but also in the muscles, for example.
The malfunction of the mitochondria in the liver causes more waste products to enter the bloodstream, which the liver normally breaks down, including ammonia in particular. Experts suspect that the increased ammonia level is linked to the development of cerebral oedema.
In addition to viral infections, salicylates and age, there may be a genetic risk for the disease. Some people are apparently more susceptible to Reye’s syndrome than others. However, the exact genetic causes are still unclear.
Examinations and diagnosis
The doctor first takes a medical history. To do this, he asks the child’s parents, for example, whether the child has recently had a viral infection and/or has taken salicylates. It is also important to describe symptoms such as vomiting, possible seizures and increasing confusion and restlessness. These are possible signs of brain involvement.
Depending on the extent of the disease, the liver may be enlarged in Reye’s syndrome, which the doctor can determine by palpating the abdomen. A blood test also provides evidence of liver involvement.
Blood test
When the liver is damaged, increased levels of liver enzymes (transaminases) and waste products such as ammonia, which the liver actually filters out of the blood and breaks down, enter the blood. In Reye’s syndrome, this leads to an increase in liver enzymes and ammonia levels.
As the liver is also responsible for the blood glucose level, a simple blood glucose test provides quick information about liver function – in Reye’s syndrome, hypoglycemia may be present.
Tissue sample
To confirm the diagnosis, the doctor may take a tissue sample (biopsy) of the liver if Reye’s syndrome is suspected and examine it for cell damage. Mitochondrial damage is particularly noticeable here. In addition, Reye’s syndrome is characterized by an increased accumulation of fat in the cells. This is a sign that the liver is no longer able to process the fat appropriately.
Other examinations
An ultrasound examination also provides information about the condition of the liver. If the doctor suspects increased intracranial pressure, he will check this with a computer tomography (CT) scan.
Reye’s syndrome is not easy to differentiate from other clinical pictures that are accompanied by similar symptoms. These include diseases that are much more common than the rare Reye’s syndrome. For this reason, the doctor often carries out further diagnostic tests, for example to rule out meningitis, blood poisoning or a serious bowel disease.
Treatment
Reye’s syndrome cannot be treated causally. The aim of treatment is therefore to alleviate the symptoms and ensure the survival of the affected child. This requires intensive medical treatment.
The work of all the body’s organs is interrelated. The kidneys and liver in particular form a well-coordinated team. In the event of sudden liver damage, there is therefore a risk of kidney failure (hepatorenal syndrome). The medical team uses medication to maintain urine excretion via the kidneys.
Heart and lung function are also closely monitored, as the brain damage sometimes requires measures such as artificial respiration.
Course of the disease and prognosis
Reye’s syndrome is very rare, but usually takes a rapid and severe course. Approximately 50 percent of affected children die. Many survivors suffer permanent damage. After surviving Reye’s syndrome, brain damage often remains, which manifests itself in paralysis or speech disorders, for example.
Prevention
As the causes have not been conclusively clarified, Reye’s syndrome cannot be prevented. However, it is important to avoid acetylsalicylic acid in children under the age of 15 if possible or to use it with particular caution.
