Updated review of reported cases of reactive airways dysfunction syndrome

A previous systematic review of the diagnosis of reactive airways dysfunction syndrome (RADS), undertaken from 1985 to 2004, found a lack of standardization of case reporting, thus misattribution of symptoms can occur.

We aimed to update the systematic review, update the list of reported causes and see whether a more structured approach to reporting has been adopted.

We undertook a systematic literature review, using the databases EMBASE and Ovid MEDLINE, with search terms 'reactive airways dysfunction syndrome' or 'asthma AND acute irritant', and reported according to PRISMA guidelines. We included papers and abstracts published from January 2005 to September 2019, and articles were grouped by the presence or absence of diagnostic features: 'definite' RADS (met Brooks' criteria) or 'possible' RADS (Brooks' criteria not met or insufficient data). We collected demographic and diagnostic data for cases, where given.

Eleven papers and six conference abstracts met the inclusion criteria, 13 of which were case series or reports, and comprised 752 cases in total; seven articles met Brooks' criteria for RADS diagnosis. A variety of agents were implicated, with chlorine or chlorine-releasing molecules most frequently reported.

A lack of standardized reporting of RADS remains. The majority of published articles and conference abstracts either do not meet, or contain insufficient data to judge against, Brooks' criteria, particularly in relation to onset of symptoms and bronchial hyper-reactivity or variability of airflow obstruction. Some novel agents are described, in keeping with recognized structural taxonomies.