Allergies are the fifth most common chronic disease in the United States affecting about 55% of the population. It is also an expensive disease in terms of allergy medications and allergy-related doctor visits ($7.9 billion). About 4 million work days are lost each year due to allergies.(1) Treatment for allergies costs $21 billion annually.(2) Many individuals with allergies also have asthma and that increases the costs, both direct and indirect. Allergic asthma is common in children. Asthma and allergies are part of the atopic expression in individuals. When stress is added to the equation, the balance tips in favour of stronger and more prolonged reactions.
Stress is defined as a state of mental or emotional strain or tension resulting from adverse or very demanding circumstances. It has also been defined as “a general body response to initially threatening external or internal demands, involving the mobilization of physiological and psychological resources to deal with them.” Stress may be physical, mental or a combination of the two. It may also be acute and short-lived or chronic. Chronic stress results in an instability in the body where reactions are no longer moderated but effect the neuroendocrine and sympathetic symptoms, causing an imbalance between Th1 and Th2 cells which can result in atopy. While causality cannot be confirmed, chronic stress may encourage atopic disease and also make control more difficult.(3)
Chronic stress has been associated with many diseases such as hypertension, diabetes, dyslipidemia, irritable bowel syndrome and cardiovascular disease. It can also result in depression and negative patterns or behaviour.
How does anxiety and psychological stress affect asthma, an atopic disease? Inflammation is the body’s most elemental form of defence. Acute stress triggers cortisol and adrenalin/noradrenalin in minutes. This causes an increased in pro-inflammatory cytokines which results in rapid cellular tissue damage. When stress become chronic, this rapid response is dulled but the inflammatory process continues leading to immune changes.
Stress and anxiety can worsen allergic reactions, particularly the late-phase reaction. Twenty-eight men with a history of allergic rhinitis were recruited. Standard skin prick tests to determine allergens were done. Blood, saliva and serum samples were taken prior, during and after low- and high-stress activities. Raised wheals were measured before and after high-stress performance. Men who were moderately anxious had wheals that were 75% larger after the high-stress test when compared with the response after the low-stress test. Men who were very anxious had wheals that were twice as big and were also four times as likely to have a stronger reaction to the skin test one day later, indicating an extended and strong late-phase reaction.(4)
Garone and colleagues studied 217 patients with asthma. All underwent standard pulmonary function test and allergen skin prick testing. The results showed that those who were anxious had significantly higher levels of atopy after exclusion of confounding factors such as age, sex, asthma severity and duration, smoking status and anxiolytic medication use.(5)
Prenatal stress has been shown to increase allergen-induced airway inflammation, airway hyper-responsiveness and asthma.(6–8) A study of 499 children whose families had a history of atopy found that maternal stress influenced an increase in IgE in their 2–3 month old infants. The study concluded that in utero exposure to chronic maternal stress could produce changes in immune reactivity in susceptible children.9 Joachim and colleagues showed that in patients with allergic asthma, psychological stress was negatively correlated with predicted percent FEV1.(10)
A meta-analysis of studies on the influence of psychosocial factors on atopic disorders found a positive association between psychosocial factors and atopic disorders and a further correlation between atopic disorders and future poor mental health.(11)
Wainwright et al. studied data from 20,854 participants between the ages of 40 and 80 years in the Norfolk cohort of the European Prospective Investigation into Cancer study. The study was restricted to the 686 who had been admitted to hospital for asthma. The researchers found that despite taking into account possible confounders such as age, sex, socioeconomic status, physical functioning health and obesity, psychosocial factors were associated with increased rates of hospital admission. The psychosocial factors included:
- harmful circumstances in childhood and adolescence
- life events during adulthood
- lack of social support
- current mood disorders
They showed that negative psychosocial factors were clearly associated with asthma hospital admissions.(12)
The evidence of research to date shows that chronic stress in genetically susceptible individuals can promote atopic diseases and still further, make the disease difficult to control. Stress management then should be a part of any treatment plan for patients with atopic diseases such as allergy and asthma.
- http://www.webmd.com/allergies/allergy-statistics Accessed 25 Feb. 2014
- http://www.epa.gov/research/gems/scinews_aeroallergens.htm Accessed 25 Feb 2014
- Montoro J, Mullol J, et al. Stress and allergy. J Investig Allergol Clin Immunol. 2009;19 Suppl 1:40-7.
- Kiecolt-Glaser JK, et al. How stress and anxiety can alter immediate and late phase skin test responses in allergic rhinitis. Psychoneuroendocrinology. 2009 Jun;34(5):670-80. doi: 10.1016/j. psyneuen.2008.11.010. Accessed at http://www.jiaci.org/issues/vol19s1/vol19s1-7.htm on February 25, 2014
- Barone S, Bacon SL et al. The association between anxiety sensitivity and atopy in adult asthmatics. J Behav Med. 2008 Aug;31(4):331-9. doi: 10.1007/s10865-008-9164-5
- Quarcoo D, Pavlovic S, Joachim RA. Stress and airway reactivity in a murine model of allergic airway inflammation. Neuroimmunomodulation. 2009;16:318–324. doi: 10.1159/000216189
- Lin YC, Wen HJ, et al. Are maternal psychosocial factors associated with cord immunoglobulin E in addition to family atopic history and mother immunoglobulin E? Clin Exp Allergy. 2004; 34(4): 548–554.
- Cookson H, Granell R, et al. Mother's anxiety during pregnancy is associated with asthma in their children. J Allergy Clin Immunol. 2009 Apr;123(4):847-53.e11. doi: 10.1016/j.jaci.2009.01.042.
- Wright RJ, Finn P, et al. Chronic caregiver stress and IgE expression, allergen-induced proliferation, and cytokine profi les in a birth cohort predisposed to atopy. J Allergy Clin Immunol.2004 Jun;113(6):1051-7
- Joachim RA, Noga O, et al. Correlation between immune and neuronal parameters and stress perception in allergic asthmatics. Clin Exp Allergy. 2008;38:283–290
- Chida Y, Hamer M, Steptoe A. A bidirectional relationship between psychosocial factors and atopic disorders: A systematic review and meta-analysis. Psychosom Med.2008;70 (1):102-16
- Wainwright NW, Surtees PG et al. Psychosocial factors and incident asthma hospital admissions in the EPIC-Norfolk cohort study. Allergy.2007;62:554-60.