**3.5 Cockroaches**

Cockroaches are a worldwide populates pest with more than 3500 species known. They are most found in cities with highest urban population. Exposure to this indoor and outdoor pest, are well known causative agents of asthma and atopy respectively, and constant exposure this have been linked to increase asthma morbidity, which makes this environmental factors highly important in the recognition and management [25]. The cause of allergy and asthma exacerbations is been cause by proteins produced by cockroaches in which can be found in feces and body fluids of this animals. It's been stipulated that almost 60% of homes in the US have cockroaches, which is a big number comparing the high incidence of asthma and allergy, so we are continuously dealing with a difficult pest every day. There are several known cockroaches' species which are Blattella germanica and Periplaneta americana, which both produce the protein responsible for asthma triggers. Several proteins been recognized are Bla g 2(inactive aspartic proteinase), Bla g 4 (calycin) and Bla g 5 (glutathione-S-transferase) [26]. With these molecular recognized proteins, we can quantify exposure levels, which will eventually help in difficult to treat patient with asthma, in which exposure or triggers have not been recognized and subsequently avoided. Cockroaches induced allergic inflammation is the main driver in asthma exacerbations and difficult to manage asthma patients, this excreted particles from this organism can gain access to the upper respiratory tract through the nose and oral cavities with dislodgment into the lungs causing allergen epithelial damage. Cockroach allergy is diagnosed with crude extract via skin testing or direct measurement of serum specific IgE to this specific allergen, in this case cockroach. This serum levels can be use to recognized other multiple specific allergens. However, even though good sanitation and successful extermination actions are taken, sustained decrease in allergens levels is difficult to accomplish. It's important to recognized other environmental factors in this patient such as constant particulate matter exposure because air pollutants can increase the allergic effect of cockroaches and other indoor allergens with a synergistic relationship, a multidisciplinary approach for recognition is recommended to be effective in management.

*Environmental and Occupational Factors; Contribution and Perspectives on Difficult to Treat… DOI: http://dx.doi.org/10.5772/intechopen.108605*

### **3.6 Cats**

There is a strong association between pet ownership and new onset asthma as well the development of allergic symptoms. Cats had been recognized as a major source of allergens for many years. They can produce numerous allergens that can trigger asthma symptoms. These allergens can be found in cats saliva, in which at the act of cats self-grooming its transfer to the skin, producing contact dermatitis changes as well can be inhaled in combination with cats dander causing asthma as well causes difficult to treat disease in patients with continuous exposure. Cats dander is another component of cats that comes from dead skin sweat glands that can suspend in the air consequently getting into the airways. As can be seen in other animal allergic sources component, cats urine can be the source of asthma, ligated with the protein Felis domesticus (Fel d 1) found in urine which can cause airway diseases as well [27]. Touching or inhaling these allergens causes overreaction of the immune system, leading to worsening of asthma symptoms. Asthma in adults differs from children in which atopy and exposure to aeroallergens are a determinant factor that could cause airway hyperresponsiveness [28]. Allergic asthma is a difficult to treat disease, however blood markers with specific IgE components which can be range from rFel d 1 which is a marker for severe asthma, and specifically indicates that is related to cats. Other components been found in asthma is rFel d 2, rFel d 4 and r Fel d7 by which its less specific for cats because it can be present in patients with dogs, horse and mice exposures [29, 30]. The best therapeutic option in this patient population is to avoid contact with animals specially cats or dogs, and very importantly to avoid indirect contact with areas that animals spent time. Keeping animals in the outdoor setting is appropriate, however allergens will remain in indoor spaces, by which aggressive hygiene needs to take part on the management.

### **3.7 Molds**

Mold is a fungal growth that spread in surfaces, where most of the will be organic matter however it's not always the case. It can be found indoors and outdoors respectively, they will most of the time look for excess moisture places which is the most common cause of indoor mold environment. Molds are well recognized allergens related to asthma exacerbations, and most of the time will go not recognized [31]. Inhaling or contact with molds can cause allergic reactions, in which can trigger asthma symptoms, which can be manifested as sneezing, throat irritation, nasal stuffiness with runny nose and watery eyes, which are active signs of ongoing allergic process. Most of the patients will recognized this early symptom and could be able to attach specific interaction with the causing allergen, however molds are more difficult to be recognized. Most of the sources of mold in indoor settings will have water leaks associated with it, such as can be seen in air conditioners and leaks from outsource of water in close buildings. Molds not only can exacerbate asthma, but they are also well recognized factor of causing fatal respiratory conditions such as hypersensitivity pneumonitis which can be acute and could lead to respiratory failure [32]. There are several home situations even outdoors that needs to take in consideration when dealing with molds, and it's the existence of plumbing leaks, roof leaks and high humidity places, mostly indoors. Management of high-risk exposure places is important in occupational environmental, by which early detection in the setting of high suspiciousness is of great importance. Regular inspection of buildings, regular schedule air conditioning cleaning, adequate ventilation of close spaces and the importance of developing a indoor environment quality

control group that will remain on top of this circumstances for adequate management [33]. Molds can produce spores which can be inhaled, that will produce allergic symptoms with upper airway predominance, this mold could weaken the natural defense mechanism o the airway that could lead to predisposition to colds and flu diseases. Special interest is been taken about molds in occupation setting environments, in which working personnel will became symptomatic in specific working areas and not at home places, in this special setting aggressive interrogation and evaluation is of most importance to prevent future exacerbations of lung diseases specially asthma.
