VOL: 102, ISSUE: 46, PAGE NO: 46
Linda Dudek, RGN, DipAsthma,
practice nurse, Abbey Medical Centre, Kirkstall, Leeds
In 2003 the South Leeds Asthma Project was established by South Leeds PCT to address the high incidence of asthma in this area of the city. As part of the project the trust started to work with an asthma and allergy treatment company, Alpine Environments, to use a home-based treatment to eradicate house dust mites (HDMs).
Alpine Treatment works by reducing the patient’s exposure to HDMs and by denaturing the faeces of these mites, whichcauses more allergic symptoms than the mite itself (www.housedustmite.org).
The home treatment involves the application of a dry heat/steam/hot-air process to all the mattresses in the home of theperson with asthma and the installation of a positive ventilation unit in their bedroom. Air treatment is continuous and theuse of protective mite-resistant mattresses, bedding covers and pillows helps prevent reinfestation of the bed. The end resultis a low-allergen sleeping environment that produces fewer allergic responses and fewer asthmatic symptoms (Levy et al, 2000).
Htut et al (2001) demonstrated that the home-based treatment used to eradicate the HDM reduced asthma symptoms andlessened the frequency of exacerbations.
During the double-blind randomised controlled trial the treatment was used in 30 homes of people with asthma aged 18-45.
The researchers found that a single treatment reduced the HDM allergen load below the World Health Organization risk levelfor sensitisation. They also found that the patient’s bronchial hyperreactivity (BHR) level was reduced fourfold (Htut et al,2001).
Following this trial the South Leeds Asthma Project, funded by Leeds Health Action Zone, decided to use the treatment insouth Leeds with the aim of reducing the dosages of regular asthma medication and improving the quality of life of people withasthma.
Selecting patients for the treatment
Participants were referred for treatment by local GPs and practice nurses. A number of patients with very severe asthmawere also referred to the project by hospital consultants.
Places on the project were allocated to adults and children, sometimes from within the same family, who had asthma andwere allergic to the HDM.
For the treatment to be effective, the patients must be atopic and have a proven allergy to the HDM (Dermatophagoides pteronyssinus). The treatment can also have benefits for people with pollen allergies due to theenvironmental filtration and the ventilation system used.
Candidates had skin-prick testing to ensure that they would benefit from the treatment. These tests involved exposure topurified solutions of known allergenic substances: HDM, cat and dog dander and grass pollen.
Informed consent was obtained and the subjects were asked not to take any antihistamine medication for 48 hours before thetest as this could affect the response.
Sticking tape markers numbered one to six were applied to the individual’s clean forearm, a drop of each allergen insolution was then applied and the skin was lightly punctured with a sterile lancet. A new lancet was used for each solution toprevent cross-contamination of the allergen.
The results of the skin-prick test were checked after 15 minutes. A positive and negative solution was used for controlpurposes. A weal of 5mm in response to HDM solution was deemed clinically significant as an allergic reaction and patients whodisplayed a positive response were recruited onto the project.
The next stage of the process involved pre-treatment serial peak flow measurement. This also included details of thepatient’s daily medication and a symptom diary to establish a baseline of lung function and how their asthma affected dailyactivity.
These details were recorded continuously for a period of two weeks.
Once the pre-treatment monitoring was completed the eradication processes were performed. This included preparation workby the patients (or their parents) - a spring clean of the whole house and decluttering of their bedrooms to help reduce thedust load. The bedding was freshly laundered at 60ºC as this temperature is deemed to be optimal for HDM removal(Platts-Mills and Arian, 2001).
Trained technicians then surface-cleaned all the carpets and soft furnishings in the houses with steam to help reduce theHDM load. The mattresses were treated and encased in HDM-proof coverings. Quilts were surface-steamed and dried with hot airbefore having HDM-proof covers applied. New anti-allergenic pillows were provided and old pillows removed and destroyed.
Air-treatment units were installed in the patients’ bedrooms. These units use multiple functions to create a low-allergenatmosphere. They filter fresh air into the rooms, act as a heat exchanger, filter airborne particles of dust and pollen, andreduce the humidity to a level where the HDM cannot survive. The whole process was completed in one day.
Studies have noted the reduction in HDM numbers with dehumidifiers but none, up to now, have confirmed any improvement inpatient symptoms (Singh et al, 2002). However, Htut et al (2001) demonstrated that, in conjunction with other environmentaltreatments, dehumidifiers can make a positive difference.
Once the treatment had been completed, the householders were given written advice on the maintenance of a low-allergenhome, focusing on simple chores such as weekly damp dusting, vacuuming and airing of bedding.
The patients’ subsequent progress were monitored for one week a month for a total of 12 months to check the efficacy andlongevity of actual and perceived improvements to health.
The treatments began in 2004 and 37 people in 30 homes now have the system installed. Following the initial treatments thepeak flow measurements of subjects have been monitored for a period of 12 months.
The final results showed significant observed improvement and analysis continues.
Results of the treatment
Patients benefited from all of these combined measures and patients noted:
- Improved sleep;
- Less sneezing;
- Less wheezing;
- Reduction of inhaler use;
- Higher energy levels;
- Fewer colds/chest infections;
- Reduction in frequency of hospitalisation;
- Less nasal congestion;
- Improved eczema.
The treatment uses a multi-pronged approach to the environment in which the person with asthma spends many hours each day.Naturally, patients will be exposed to high levels of allergens once they are outside the home, but a substantial period oftime each day in which allergenic triggers are controlled is beneficial.
People with asthma and especially children who have other atopic conditions such as eczema, or where there is a strongfamily history of atopic conditions, could undoubtedly benefit from a reduction in HDM load.
Healthcare professionals should consider providing parents and adults with asthma with general advice on how to reduce theHDM load and the general allergen exposure in their home environment through:
- Regular damp dusting;
- The replacement of curtains with blinds and the replacement of carpets with hard floor coverings;
- Minimising soft toys and periodically freezing those provided.
Environmental modification to reduce known allergens appears to be a highly effective treatment for certain types ofasthma and allergic reaction.
The Alpine Treatment costs £1,000 and needs to be carried out only once. The only maintenance required afterwards isto change the filters on the ventilation system.
The government announced in March that it planned to cut repeat emergency admissions for chronic conditions such asasthma.
This clinically tested, drug-free, chemical-free treatment for allergic asthma sufferers improves symptom control andenables patients to have greater self-management.
In conjunction with regular supervision by primary care health professionals such as asthma nurses, this could reduceexacerbations and lessen the need for secondary care intervention.
Htut, T. et al (2001) Eradication of house dust mites from homes of atopic asthmatic subjects: a double-blind trial.Journal of Allergy and Clinical Immunology; 107: 1, 55-60.
Levy, M. et al (2000) Asthma at Your Fingertips. London: Class Publishing.
Platts-Mills, T.A.E., Arian, L.G. (2001) The biology of dust mites and the remediation of mite allergens inallergic disease. Journal of Allergy and Clinical Immunology; 107: 3, S406-S413.Singh, M. et al (2002) Humidity control for chronic asthma. Cochrane Database of Systematic Reviews; Issue 1. Art. No:CD003563. DOI: 10.1002/14651858.CD003563.