Practical Allergen Avoidance and Exposure Reduction Strategies
Allergen avoidance and environmental control measures aim to decrease exposure to aeroallergens and irritants to reduce the severity of symptoms (Table 2). 37,38,39,40 The major outdoor allergens are pollens and fungal spores, while the major indoor allergens include HDM, pets, moulds and cockroaches. Avoidance measures can be cumbersome, expensive and not always practical, and hence, allergen se
Allergen avoidance and environmental control measures aim to decrease exposure to aeroallergens and irritants to reduce the severity of symptoms (Table 2).37,38,39,40 The major outdoor allergens are pollens and fungal spores, while the major indoor allergens include HDM, pets, moulds and cockroaches. Avoidance measures can be cumbersome, expensive and not always practical, and hence, allergen sensitisation needs to be proven before advising on allergen reduction strategies.
TABLE 2: Environmental control and allergen avoidance measures.
| Allergens | Control and measures |
| House dust mites | - Use occlusive air-permeable fabric protectors for pillows, mattresses and duvets. - Bedding should be washed in hot water and exposed to direct sunlight. - Replace carpets with wooden floors or tiles. - Loose carpets should be cleaned regularly and sun dried - Vacuum with a vacuum cleaner with a high-efficiency. particulate air (HEPA) filter – adequate disposal of vacuum bag is important thereafter. - Vacuum cleaning increases room dust, so a mask should be worn while vacuuming – leave the room for 20 min after vacuuming. - Remove soft toys from the bedroom. - Air conditioners are not advisable, as filters often contain house dust mite allergens, which may be recycled through rooms. - Benzyl benzoate, tannic acid, acaricides and other anti-mite sprays have very little or unproven benefit. - Humidifiers increase mould and HDM. |
| Cockroach | - Do not leave food open overnight. - Do not leave dishes in the sink overnight. - Seal cracks and crevices. - Vacuum or sweep the floor after every meal. - The use of professional exterminators is advised. - Use cockroach traps. |
| Pet allergens | - Removal of pets only after proof of sensitisation with clinical symptoms directly related to pet exposure (patients and families are unlikely to adhere to this). - Regular washing of pets. - Keep pets out of the bedroom. - Frequent vacuuming with vacuum cleaner equipped with a HEPA filter. - Encase pillows and mattresses. - There is no evidence that any breed of dog or cat is hypoallergenic. |
| Indoor moulds | - Ensure adequate ventilation. - Limit the number of indoor plants. - Clean mould-infested surfaces with bleach. - Repair of leaks. - Removal of water-damaged materials. - Run (exhaust) vents advisable in bathroom and kitchen. - Regular vacuuming may reduce fungal spores, but replacing carpets with other types of flooring seems more effective. |
| Outdoor allergens (pollens and fungal spores) |
- Avoid outdoor activities and wear masks outdoors during peak pollen and mould periods by consulting pollen calendars and pollen forecasts/monitoring websites. - Keep doors and windows closed. - Change clothing when returning home. - Mould-sensitive patients should avoid contact with decomposing leaves, grasses and grains. |
Source: Please see the full reference list of the article Kalayci O, Miligkos M, Pozo Beltrán CF, et al. The role of environmental allergen control in the management of asthma. World Allergy Organ J. 2022;15(3):100634. https://doi.org/10.1016/j.waojou.2022.100634, for more information
Note: Further information on reduction of common allergens is available on the Allergy Foundation website –https://www.allergyfoundation.co.za/patient-information/en/allergens/.HDM, house dust mites.
Click here to access the PDF.
Richards GA, McDonald M, Gray CL, et al. Allergic rhinitis: Review of the diagnosis and management: South African Allergic Rhinitis Working Group. S Afr Fam Pract. 2023;65(1), a5806. https://doi.org/10.4102/safp.v65i1.5806