High-altitude treatment has a long history and has been used in treating pulmonary conditions for more than a century. The first TB patients started to come to Davos in 1865. The climatic conditions of the high mountains, the quiet and the distance from sources of tuberculosis infection turned out to be curative. Some patients had asthma in addition to TB and experienced relief from symptoms in a time when there was still no medication for asthma available. After the Second World War, tuberculostatics made the treatment of TB patients in high-altitude clinic unnecessary.
Prednisolone came onto the market to treat asthma, and for a time it also seemed that high-altitude treatment for asthma patients was unnecessary. However, despite great developments in asthma medication, there remained a group of patients from whom high-altitude treatment was still necessary.
This in turn created scientific interest in the question:
What does the mountain climate mean in the diagnosis and treatment of asthma?
In 1927 Storm van Leeuwen developed the hypothesis about the influence of “climate allergens” on asthma patients. Later, it emerged that dust mites also play a significant role. Dust mites cannot survive in the dry mountain climate of Davos. In 1967 Kerrebijn and Zuidema showed that during high-altitude treatment, oral steroids could be reduced in prednisolone-dependent children with asthma over the course of 3 months. Hyper-reactivity of the airways showed steady improvement over 12 months.
From the nineteen eighties, inhalation steroids became readily available on a large scale and the asthma problem seemed to be definitively solved. But not for every patient! In 2001, Grootendorst demonstrated that allergic children who were symptomatic despite high doses of inhalation steroids reacted favourably during a stay in a high-altitude location. Young adult patients, also with serious but non-allergic asthma, showed improvements in inflammation and infection, in both clinical and functional parameters.
The lack of dust mites has turned out not to be the only high-altitude factor that contributes to relief from asthma. The dry mountain climate also has lower levels of fungal spores, pollen and air pollution. In addition, there is also higher exposure to UV light which modulates the immune system and inhibits inflammation and infection. The influence of environmental factors as a therapeutic option has somewhat been lost sight of through the complexity and moderate effectiveness of housing improvement measures in the Netherlands, but can play an important role with the groups of patients who, despite maximum treatment, remain symptomatic.
Scientific research into the effect of high-altitude treatment for allergic patients has been supplemented in recent years with research among non-allergic patients. The effect of high-altitude treatment among non-allergic patients was compared with the effect on allergic patients. Both groups showed a corresponding significant improvement in asthma control and quality of life, reduction of upper airway complaints, and improved lung function and tolerance to exertion. Almost half of the patients with a dust mite allergy and a third of the non-allergic patients could completely cease taking the maintenance dose of prednisolone, while the dosage could be considerably reduced among the other patients. Based on these results, we can conclude the high-altitude treatment of asthma in both allergic and non-allergic patients is improved and the possibility of leading as normal a life as possible at home is increased.
New medicines, such as monoclonal antibodies against IgE (omalizumab) and Interleukine-5 (mepolizumab), when compared to these high-altitude results, seem to bring about fewer improvements in quality of life. Other non-pharmacological treatments, such as bronchial thermoplasty, also bring about limited improvements in this heterogeneous group of patients with serious and difficult to control asthma.
- In collaboration with Dr L. Bel of the AMC, Academic Medical Centre Amsterdam, L. Rijssenbeek-Nouwens has carried out scientific research into the effectiveness of high-altitude treatment and written the dissertation Asthma control, patient and environment.
- In collaboration with the Merem Astmacentrum Heideheuvel, under the leadership of Professor Dr J.W. Lammers of the UMC, research has been carried out since September 2015 into the added value of treatment in high altitudes in relation to treatment of patients with serious asthma at sea level.
- In collaboration with Professor J. Sont, we are researching the extent to which aftercare supported by the Internet can be effective in the PRACTISS study: Pulmonary Rehabilitation of Asthma and COPD: a Trial of sustained Internet-based Self-management Support (PRACTISS).
- Under the leadership of Prof Dr CAFM Bruijnzeel-Koomen and Prof Dr SGMA Pasmans, K. Fieten has carried out scientific research into the effectiveness of high-altitude treatment in children with serious eczema and asthma. The DAVOS study is the first randomised study which demonstrates the effectiveness of high-altitude treatment. In K. Fieten’s dissertation entitled “Complex care for complex eczema in children”, the results of the DAVOS study are described as well as other publications.