Allergic Asthma

Abstract

Allergic asthma, also known as atopic asthma, is one type of extrinsic asthma that is characterized by an exaggerated immune response to a variety of indoor and outdoor allergens. The most commonly associated indoor allergens are house dust mites, cockroaches, and animals such as cats. However, outdoor ­allergens such as alternaria mold, ragweed, tree, and grass pollen are also known triggers. The relationship between asthma and allergy is very complex, and atopic individuals­ seem to be at increased risk for asthma [1]. The clinical presentation of asthma can vary greatly and depends on the stage and severity of the underlying disease ­process. The development of allergic asthma is dependent on the T-Helper two (TH₂) ­predominant immune response. The diagnosis of allergic asthma must be made clinically with consistent history and observed worsening of the condition following­ exposure to a suspected allergen. Diagnostic testing, in general, is often not needed to make the diagnosis if the history is compelling. Pulmonary function testing (PFT) reveals the classic obstructive pattern of asthma with observed reversibility following administration of beta₂ agonists. Specific sensitivity to suspected allergens can be ascertained by interpretation of skin prick testing or serum specific IgE levels. Treatment involves removing, if possible, the inciting allergens. Other treatments involve ones typically utilized in any asthmatic such as inhaled corticosteroids and beta₂ agonists. In some patients airway remodeling can occur if the inflammatory response is left unchecked; therefore, controlling the underlying inflammation is imperative.