Thunderstorm Asthma

11 February 2019
Thunderstorm Asthma


Do we need guidelines for prophylactic treatment as the season approaches and is there a role for prophylaxis guidelines in pollen sensitized asthmatics during the thunderstorm season?


By Mona Al-Ahmad, MD

Thunderstorm-induced asthma has been described as an observed increase in acute bronchospasm cases following thunderstorms in the local vicinity. Thunderstorms are considered a risk factor for asthma attacks in patients suffering from pollen allergy as evidenced by the occurrence of severe asthma epidemics during thunderstorms in the pollen season. Asthmatic patients allergic to pollen who stay indoors during thunderstorms and non-allergic subjects are not as affected. 

D’Amato et al concluded that 1) there is a temporal association between the start of the thunderstorm and the onset of asthma exacerbations; 2) Asthma epidemics related to thunderstorms are limited to pollen (and outdoor mould) seasons; 3) Subjects with pollen allergy who stay indoors with the window closed during thunderstorms are not involved; 4) patients who are not receiving asthma treatment and those with allergic rhinitis and without previous asthma can experience severe bronchoconstriction 5) and non-allergic subjects are not involved in thunderstorm-related asthma.

Prevention by avoiding exposure by remaining indoors has predominantly been the advice offered to highly sensitized individuals during severe thunderstorms. Could guidelines regarding adjustments in medication in this subset of individuals during this season improve outcomes? Identifying this subset of patients can prove challenging given patients without asthma symptoms, but affected by seasonal rhinitis are also at risk of asthma exacerbation. Is it possible to predict thunderstorm-related asthma?



  1. Cockcroft, Donald W. et al.Thunderstorm asthma: An allergen-induced early asthmatic response. Annals of Allergy, Asthma & Immunology , 2016; Volume 120 , Issue 2 , 120 – 123
  2. D'Amato G, Vitale C, D'Amato M, Cecchi L, Liccardi G, Molino A, Vatrella A, Sanduzzi A, Maesano C, Annesi-Maesano I.  Thunderstorm-related asthma: what happens and why.  Clin Exp Allergy. 2016 Mar;46(3):390-6. 
  3. D’Amato G, Cecchi L, Annesi-Maesano I. A trans-disciplinary overview of case reports of thunderstorm-related asthma outbreaks and relapse. Eur Respir Rev 2012; 21:82–7.


Other Resources:

March 13, 2015
Spring Season Asthma vs. Thunderstorm Asthma

I see a lot of patients with spring seasonal asthma every year in Australia, but so-called "thunderstorm asthma" cases are few and occur in mini-epidemics. Is there a difference in the pathogenesis of these two forms of asthma?

From the Editors: Two experts discuss the concept of "Thunderstorm Asthma" which can primarily occur during pollen seasons. While conventional thought is that rains washes away the pollen with subsequent decrease in symptoms, hard rain may actually increase symptoms as the result of breaking up larger pollens into smaller particles.

By Professor Wayne Thomas

Pollen exposure during pollen seasons induces asthma as well allergic rhinitis in allergic subjects and in even the absence of thunderstorms increased hospital admissions are associated with high pollen days (1). A number of statistical analyses have documented spikes of asthma-driven hospital visits to emergency departments associated with thunderstorms in the pollen season as recently reviewed in detail (2). Some episodes have been very noticeable resembling mini-epidemics. Although people who have not previously had asthma have had asthma attacks the subjects affected by the thunderstorms are pollen allergic subjects and the exacerbations resolve uneventfully.

Several plausible but unproven proposals could explain the asthma spikes (3,4). The rain could collect the pollen from the air transporting it down into layers where humans breathe and further the rain can disrupt the pollen grains leading to sub-pollen particles that are not only more readily inhaled but contain a higher concentration of constituents such as reactive oxygen species that enhance inflammation and other tissue responses. This might be further associated with direct effects of the weather such as the inhalation of cold air and a concentration of irritants transported by the rain into the breathing zone. To date however there is no evidence that the thunderstorm asthma of pollen allergic subjects is qualitatively different to that found in pollen seasons and pollen species associated with the thunderstorm asthma are those prevailing in the region at the time of the event (2).

One difference that has been corroborated is that the number of subjects allergic to fungal spore allergens is over represented in thunderstorm asthmatics (2). The subjects are allergic to the commonly encountered outdoor fungi of Penicillium, Cladosporium, Alternaria and Aspergillus species that sporulate in the spring and summer and without thunderstorms can produce levels of spores that associate with asthma exacerbations (5). Several investigations have found that mould-allergic subjects suffer from more severe asthma (6) so it is possible that it is more easily exacerbated or alternatively the presentation of fungal allergens is more affected by the thunderstorm than the pollen.


  1. Erbas B. Akram M. Dharmage SC. Tham R. Dennekamp M. Newbigin E. Taylor P. Tang ML. Abramson MJ. The role of seasonal grass pollen on childhood asthma emergency department presentations. Clinical & Experimental Allergy. 42(5):799-805, 2012
  2. Dabrera G. Murray V. Emberlin J. Ayres JG. Collier C. Clewlow Y. Sachon P. Thunderstorm asthma: an overview of the evidence base and implications for public health advice. Qjm. 106(3):207-17, 2013
  3. Nasser SM. Pulimood TB. Allergens and thunderstorm asthma. Current Allergy & Asthma Reports. 9(5):384-90, 2009
  4. Taylor PE. Jacobson KW. House JM. Glovsky MM. Links between pollen, atopy and the asthma epidemic. International Archives of Allergy & Immunology. 144(2):162-70, 2007
  5. Atkinson RW, Strachan DP, Anderson HR, Hajat S, Emberlin J. Temporal associations between daily counts of fungal spores and asthma exacerbations. Occup Environ Med. 2006 September; 63(9): 580–590
  6. Downs SH. Mitakakis TZ. Marks GB. Car NG. Belousova EG. Leuppi JD. Xuan W. Downie SR. Tobias A. Peat JK. Clinical importance of Alternaria exposure in children. American Journal of Respiratory & Critical Care Medicine. 164(3):455-9, 2001

Wayne Thomas, PhD
Centre for Child Health Research
University of Western Australia
Telethon Institute for Child Health Research
Perth Australia


By Dr Jonathan Bernstein

Thunderstorm asthma attacks are quite different from seasonal allergic asthma.  During the pollen season when the weather is calm, the pollen granules are too large to get into the small airway of the lungs and are typically filtered out through the nose causing more often problems with allergic rhinitis symptoms rather than asthma.  However, during thunderstorms, the pollen granules are broken up into particles small enough that allow them to get into the small airways which can exacerbate asthma.  The smaller pollen particles are concentrated at the ground level where they can be more easily inhaled and get into the airways causing an asthma attack.  Thunderstorm asthma attacks typically have a quick onset of action and are associated with more severe asthma symptoms such as wheeze, chest tightness, shortness of breath and cough.  Most individuals predisposed to thunderstorm asthma attacks have been found to have seasonal allergic rhinitis.  However, if the patient’s asthma is well controlled on medications such as inhaled corticosteroids without or with long acting beta agonists depending on the severity of their asthma, then thunderstorm asthma attacks can be significantly attenuated or prevented.


  1. Girgis ST, Marks GB, Downs SH, Kolbe A, Car GN, Paton R. Thunderstorm-associated asthma in an inland town in south-eastern Australia. Who is at risk? Eur Respir J. 2000 Jul;16(1):3-8.
  2. D'Amato G, Liccardi G, D'Amato M, Holgate S. Environmental risk factors and allergic bronchial asthma. Clin Exp Allergy. 2005 Sep;35(9):1113-24.

Jonathan Bernstein, MD
Professor of Medicine Department of Internal Medicine
Professor of - Division of Allergy & Immunology
Bernstein Allergy Group
Cincinnati, Ohio, USA


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