Dr. Mohammed Ashraf Puthiyachirakkal - Consultant Pediatrician and Neonatologist, Al Zahra Hospital Sharjah
One of the most common diseases a Pediatrician encounter in the clinic is asthma. Incidence and prevalence are increasing, most likely due to better recognition and diagnosis; changing environmental factors such as increased allergens, and changing lifestyle factors including increased stress.
Asthma can be diagnosed at any age, but the majority (80%) of children have symptoms within the first six years of life. Two-thirds to three-fourths of pre-school aged children who are early wheezers will not continue to wheeze beyond 5 years of age. However, risk of persistent asthma between six and 13 years significantly increases if the child has a history of eczema by 2-3 years of age, parental history of asthma OR two of the following including a) physician diagnosed allergic rhinitis by 2-3 years of age, b) >4% peripheral eosinophils, or c) wheezing not associated with upper respiratory tract infection.
The primary underlying mechanism responsible for asthma is airway inflammation. Airway inflammation causes airway hyper-responsiveness (bronchoconstriction/bronchospasm) and lower airway obstruction, as well as edema, mucus production and recruitment of inflammatory cells into the airway
Viral respiratory infections are the most common cause of asthma exacerbations (accounting for upwards of 80% of all asthma exacerbations). Allergen exposure also commonly precipitates asthma exacerbations, with the subsequent bronchospasm occurring in two phases. In the early phase, occurring approximately 15 minutes after exposure, increasing histamine and leukotrienes and leading to bronchoconstriction. Released cytokines and chemokines also stimulate migration of inflammatory cells to the airways, thereby increasing edema and mucus production and causing a second phase (4-12 hours after the exposure) of bronchospasm.
Diagnosis: Asthma is primarily a clinical diagnosis. Diagnosed by having following symptoms-
1. Episodic symptoms of airflow obstruction or airway hyper-responsiveness are present.
2. Airflow obstruction is at least partially reversible (as determined by spirometry in children ≥5 years).
3. Alternative diagnoses are excluded
Sometimes children with asthma can present with a history of chronic cough, but no history of wheezing. The diagnosis of asthma can be made when the patient responds to an empiric trial of asthma medications. If the cough does not respond to short-acting beta-agonist, then a trial of low dose inhaled corticosteroids can be helpful. In addition, patients with cough-variant asthma may demonstrate responsiveness to bronchodilator with pre- and post-bronchodilator spirometry.
The diseases which mimics asthma: chronic sinusitis, allergic rhinitis, foreign body obstruction, vocal cord paralysis or dysfunction, vascular rings or slings, laryngotracheomalacia, enlarged mediastinal lymph node or tumor, viral infection, CF, cardiac disease and aspiration.
Management: Treatment goals are to maximize the quality of life and minimize morbidity. In general, if a patient is classified with asthma that is persistent (mild, moderate or severe) or that is not well-controlled, he/she should be treated with either: a) a daily controller medication (e.g., inhaled steroid or leukotriene modifier); or b) placed on a more intensive daily controller medication regimen.
Environmental Control: Atopy has been found to be one of the major predictors of persistent asthma. Therefore, environmental interventions are an important aspect of management for many patients. Essentially, this involves reducing exposure to irritants and allergens in the child's environment. Every child with persistent asthma should be tested for allergies; allergy testing also may be beneficial in some children with intermittent asthma.
Tobacco smoke: The incidence of asthma is increased in children who live in a home where a parent smokes. Such children have more frequent emergency room visits, a higher requirement for medication and poorer pulmonary function. Parents need to be provided with this information and encouraged to be active about stopping smoking.
House dust mite: One gram of house dust may contain as many as 1,000 mites and 250,000 fecal pellets. The mites live on human dander, or skin flakes, and are found in high levels in dust obtained from mattresses, pillows, carpets, upholstered furniture, bed covers, clothes and soft toys. House dust mites are dependent upon a humid environment for their survival. Reducing exposure to house dust mites has been shown to reduce asthma symptoms. There are many different means of reducing exposure though many of these may be difficult due to the expense:
1. Encase the mattress and box springs and pillows in allergen-proof encasements
2. Wash all of the bedding, including comforters, blankets, etc., in hot water every 1-2 weeks
3. Avoid sleeping or lying on upholstered furniture
4. Remove carpets that are laid on concrete
5. Remove carpet from the bedroom
6. Do not sleep with stuffed animals.
7. Use an under-blanket and wash it frequently.
8. Maintain a dry environment (relative humidity 45% or less)
Cockroach & Rodents: Integrated pest management (IPM) along with rodenticide is an approach to addressing cockroach and rodent infestation
Furred Pet Allergens: All breeds of cats and dogs produce common allergens. The allergens are contained in the animal’s dander and saliva. Relief may not be apparent for several months after removal of animals, as the allergens persist in dust reservoirs and substantial reductions in allergen levels are not seen for at least 4-6 months
Pollens and molds: Exposure to outdoor allergens is best reduced by remaining indoors. Pollen and some mold counts tend to be highest during the midday and afternoon, so this may be a good time to be indoors