[2] Death occurs in 20–40% of those affected with Reye syndrome, and about a third of those who survive are left with a significant degree of brain damage.

The diagnosis of Reye syndrome greatly decreased in the 1980s, when genetic testing for inborn errors of metabolism was becoming available in industrialized countries.

[15] In some countries, oral mouthcare product Bonjela (not the form specifically designed for teething) has labeling cautioning against its use in children, given its salicylate content.

[18] Current advice in the United Kingdom by the Committee on Safety of Medicines is that aspirin should not be given to those under the age of 16 years, unless specifically indicated in Kawasaki disease or in the prevention of blood clot formation.

The recovery of adults with the syndrome is generally complete, with liver and brain function returning to normal within two weeks of onset.

[citation needed] In 1980, after the CDC began cautioning physicians and parents about the association between Reye syndrome and the use of salicylates in children with chickenpox or virus-like illnesses, the incidence of Reye syndrome in the United States began to decline, prior to the FDA's issue of warning labels on aspirin in 1986.

For the period 1991–1994, the annual rate of hospitalization due to Reye syndrome in the United States was estimated to be between < 0.3 – 1 per million population less than 18 years of age.

[citation needed] From November 1995 to November 1996 in France, a national survey of pediatric departments for children under 15 years of age with unexplained encephalopathy and a threefold (or greater) increase in serum aminotransferase and/or ammonia led to the identification of nine definite cases of Reye syndrome (0.79 cases per million children).

Also in 1964, George Johnson and colleagues published an investigation of an outbreak of influenza B that described 16 children who developed neurological problems, four of whom had a profile remarkably similar to Reye syndrome.

In 1979, Karen Starko and colleagues conducted a case-control study in Phoenix, Arizona, and found the first statistically significant link between aspirin use and Reye syndrome.

[25] Studies in Ohio and Michigan soon confirmed her findings[26] pointing to the use of aspirin during an upper respiratory tract or chickenpox infection as a possible trigger of the syndrome.

Beginning in 1980, the CDC cautioned physicians and parents about the association between Reye syndrome and the use of salicylates in children and teenagers with chickenpox or virus-like illnesses.

Surgeon General issued an advisory, and in 1986, the Food and Drug Administration required a Reye syndrome-related warning label for all aspirin-containing medications.