Figures
- Figure 1.
Parietaria pollen.
Tables
- Table 1. Thunderstorm asthma studies
Country Study year Event Comments UK [3] 1983 26 sudden cases of asthma attacks Increased risk of asthma in relation to thunderstorms Australia [14] 1992 Hospital attendances and admissions because of asthma exacerbation Late spring thunderstorms in Melbourne can trigger epidemics of asthma attacks (five to 10-fold rise) The seasonal nature of the phenomenon and the pattern of allergic responses found in affected patients suggests a possible aetiological role for rye grass pollen UK [15] 1997 Asthma or other airways disease hospital visits 640 cases who attended during a 30-h period from 18:00 h on June 24, 1994, nearly 10 times the expected number Canada [16] 1992–2000 18970 hospital ED asthma visits among children 2–15 yrs of age Summer thunderstorm activity was associated with an OR of 1.35 (95% CI 1.02–1.77) relative to summer periods with no activity USA [17] 1993–2004 215832 asthma ED visits; 24350 of these visits occurred on days following thunderstorms Significant association between daily counts of asthma ED visits and thunderstorm occurrence
Asthma visits were 3% higher on days following thunderstormsAustralia [18] 2000 Asthma visits during thunderstorms History of hay fever and allergy to rye grass are strong predictors for asthma exacerbation during thunderstorms in spring Australia [19] 2001 Hospital attendances for asthma The incidence of excess hospital attendances for asthma during late spring and summer was strongly linked to the occurrence of thunderstorm outflows UK [20] 2002 A case–control study of 26 patients presenting to Cambridge University Hospital with asthma after the thunderstorm Alternaria alternata sensitivity is a compelling predictor of epidemic asthma in patients with seasonal asthma and grass pollen allergy and is likely to be the important factor in thunderstorm-related asthma Italy [21] 2004 ED asthma Six cases of thunderstorm-related asthma because of pollen (Paretaria) Italy [22] 2010 ED asthma 20 cases of thunderstorm-related asthma because of pollen (olive tree) Australia [23] 2010 Epidemics of “thunderstorm asthma” that occurred in Melbourne during spring 2010 The approach of spring, together with high winter rainfall in and around Melbourne that heralds another severe pollen season, raises the risk of allergic rhinitis and asthma in pollen-sensitive individuals ED: emergency department; OR: odds ratio.
- Table 2. Characteristics of documented epidemics of thunderstorm-associated asthma
There is a link between asthma epidemics and thunderstorms The epidemics related to thunderstorms are limited to seasons when there are high atmospheric concentrations of airborne allergenic pollens There is a close temporal association between the start of the thunderstorm and the onset of epidemics There are not high levels of gaseous and particulate components of air pollution during thunderstorm-related asthma outbreaks Subjects with pollen allergy who stay indoors with the window closed during thunderstorms are not involved There is a major risk for subjects who are not receiving anti-asthma treatment but subjects with allergic rhinitis and without previous asthma can experience severe bronchoconstriction There are no observations on the involvement of asthma in nonallergic subjects - Table 3. Hill's criteria [32] applied to thunderstorm-related asthma
Hill's criteria Application to the thunderstorm-related asthma Temporal relationship Thunderstorms always precede asthma attacks Exposure always precedes the outcome Strength Increased risk of asthma attacks in relation to thunderstorms The stronger the association, the more likely it is that the relationship of the factor to the health outcome is causal Dose–response relationship An increasing amount of exposure increases the probability of the health outcome Of note, the absence of a dose–response relationship does not rule out a causal relationship Increased amount of pollen and mould spores at the beginning of the thunderstorm associated with increased probability of asthma attacks in pollen patients and other allergic patients Consistency The association is consistent when results in different studies and among different populations Association between thunderstorm and asthma found in different studies and different populations Plausibility The association agrees with currently accepted understanding of pathological processes Evidence of biological plausibility at the basis of thunderstorm-related asthma through pollen exposure (allergens and starch granules in the cytoplasm or other paucimicronic cytoplasmic-components carrying allergens)
Evidence to be established in the case of mould sporesConsideration of alternate explanations Alternate hypothesis involving chemical air pollution less explanatory than thunderstorm-related asthma It is necessary to consider multiple hypotheses before making conclusions about the causal relationship between any two items under investigation Experimental Evidence indicating that prevention is possible by avoiding exposure to thunderstorm (at its beginning) in pollen patients The condition can be altered (prevented or ameliorated) by an appropriate experimental regimen Specificity Poorly shown by experimental data (also sparse and heterogeneous) This is established when a single putative cause produces a specific effect Coherence Existing theory and knowledge support the existence of thunderstorm-related asthma The association should be compatible with existing theory and knowledge
Vol 21 Issue 124
Table of Contents
A trans-disciplinary overview of case reports of thunderstorm-related asthma outbreaks and relapse
