Near-fatal asthma: a heterogeneous clinical entity.

Purpose of Review: The aims of the present review were to describe the heterogeneous nature of near-fatal asthma (NFA) and to summarize the distinctive phenotypes identified in this subtype of asthma.
Recent Findings: Clinical, physiological, and histological studies have shown a large number of triggers, pathological mechanisms, and risk factors associated with NFA. Based on the demographic and clinical characteristics of the patients, the circumstances surrounding the asthma exacerbation and some distinctive features of the disease, several clinical profiles of asthma patients with NFA have been described. Recent data show new associations between some gene expression patterns and fatal asthma, as well as with some biological markers related to inflammatory or immunologic mechanisms in the airways. Also, the use of statistical methods, such as cluster analysis, allowed identifying and confirming different phenotypes of life-threatening asthma patients.
Summary: NFA is a heterogeneous clinical entity, in which different patients' clinical profiles may coexist [e.g. rapid-onset NFA, NFA in patients with dyspnea hypoperception or sensitized to certain pneumoallergens (Alternaria alternata, soybean), NFA related to the menstrual cycle, brittle asthma]. Knowledge of these phenotypes as well as adequate and specific management strategies can reduce morbidity and mortality in patients suffering from NFA.