19 February 2020 Are environmental control measures important? The incidence and prevalence of allergic diseases have increased dramatically in recent decades. Allergy is an overreaction of the immune system to substances to which most people do not react to. These substances are called allergens . One of the pillars bases of allergic diseases treatment is the avoidance of contact with the allergen and the measures to be adopted for this avoidance are called environmental control measures . It has been shown that the more allergic a patient is, the greater the benefit of environmental control measures. The type of measures that should be taken by an allergic patient depends on their disease and sensitivity profile. Allergens from the outside environment: what are they? Pollens and fungi are the most important allergens in the outdoor environment that induce symptoms of allergic disease (for example, allergic rhinitis and allergic asthma). Atmospheric conditions determine the aggressiveness of these agents: — Rainy periods drastically reduce their concentration in ambient air; — The high temperature, dry weather and wind are favorable to its spread and induce more severe symptoms. How to avoid exposure to pollens? When concentration of pollens in the air is high , the following measures should be adopted: Avoid areas of high pollination; During sunny and windy days and in periods of high temperature, avoid walking near trees, lawns or weeds (for example, gardens and city parks); Minimize outdoor activity very early in the morning, when there is more release of pollens; In days with high pollen counts, avoid outdoor sports, camping, hunting or fishing; Stay indoors, with the door and windows closed, when pollen counts are high, and in hot, dry and windy days; Keep home and car windows closed; Wear sunglasses outdoor to protect your eyes and prevent eye symptoms; When you arrive home, change your clothes, brush your hair, wash your face, hands and, ideally, take a shower; Motorcyclists should wear a full helmet; Have your relief medication available. Pollen bulletins can be consulted at www.spaic.pt Indoor allergens: what are they? Household dust is the most important source of indoor allergens. It is a very heterogeneous mixture of debris, including animal, vegetable, bacterial and fungal derivatives, among others. In domestic powder, the following stand out for their importance: Mites The mites found in the house dust are less than 0.5 mm. They multiply quickly in hot and humid environments. They accumulate mainly on mattresses, pillows, blankets, rugs, carpets and sofas. Although they are present throughout the year, the spring and autumn months, due to the humidity and temperature conditions, allow high survival and reproduction rates for mites, which thus contributes to the increase of the allergenic load. Low altitude and proximity to sea or river areas are also factors that result in higher concentrations of mites. How to avoid contact with mites? Keep the bedroom and bed well ventilated; Vacuum the mattress frequently (at least twice a week); Pillows should be washed every 4 months and replaced every 2-3 years; Prefer bed linen - sheets and bedspreads - in cotton or polyester. Avoid blankets, down blankets and down comforters; Wash the bed linen at a temperature above 60 o C; Wash clothes that have been stored for a long time before using it; Avoid having objects that accumulate dust (books, bibelots) exposed at home; Prefer vacuuming the floor (rather than sweeping) and, if possible, using HEPA filters (high efficiency particulate arrestance); Specific anti-allergic mattress and pillow covers have been shown to be effective; Putting woolen clothes, blankets and soft toys for 24 hours in the fridge or freezer, and then washing it with running water or in the washing machine, reduces the presence of mites in these textiles; Direct exposure of clothing, rugs and mattresses top sun is an effective method to reduce the presence of dust mites. Fungi Fungi, of different species, are microscopic organisms. They are transported by air and act as allergens. The humidity and temperature conditions typical of spring and autumn are ideal for fungi to reproduce. How to avoid contact with fungi? Ventilate the home environment by opening the windows and allowing fresh air and sunlight to enter; Keep the bathroom ventilated and dry, especially after bathing; Use a dehumidifier if there is a lot of humidity; Use products against moisture (anti-fungal paint). Domestic animals Cats, dogs, rabbits, hamsters, ornamental birds, among other animals kept indoors, can be important allergy inducers due to the spread of hair and skin debris, but also urine and saliva, that are very important sources of allergens. How to avoid contact with pet hair? Avoid the presence of animals in the home or confine them to restricted areas of the home; Do not allow the presence of animals in the room; Wash and brush animals frequently. The efficacy of avoiding household allergens may not be achieved with just an avoidance measure. Whenever possible, these measures should be implemented in association with a general strategy against allergenic load. The authors of this text are the following allergologists from the Hospital da Luz network: Luís Miguel Borrego, Ana Morais Mendes, Ana Reis Ferreira, Andreia Ferrão, Carlos Braga, Cristina Lopes, Diana Pereira da Silva, Filipa Semedo, Isabel Costa Silva, João Gaspar Marques, Pedro Carreiro Martins, Marta Salgado, Nuno Sousa, Rosa Anita Fernandes, Susana Piedade The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
