Canadian Allergy & Immunology Today

A Practical Approach to NSAID Allergy

David Fahmy, MD, Andrew Wong-Pack, MD — Thu, 19 Dec 2024 00:00:00 +0000

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed for pain management and inflammation. Acetylsalicylic acid (ASA) is a commonly used treatment for cardiovascular diseases including acute coronary syndromes. Reactions to NSAIDs can vary widely, ranging from exacerbation of underlying cutaneous and respiratory conditions to anaphylaxis and delayed hypersensitivity reactions (DHRs). A thorough clinical history is essential for diagnosing NSAID hypersensitivity, with a focus on the systems involved, reaction timing, and the presence and control of comorbid allergic conditions. Although commonly referred to as an allergy, the mechanisms behind these reactions are not solely IgE-mediated. As such, the authors will primarily use the term “hypersensitivity reactions” in concordance with the latest American Academy of Allergy, Asthma and Immunology (AAAAI) drug allergy practice parameter. While NSAID hypersensitivity reactions may cross-react among cyclooxygenase-1 (COX-1) inhibitors, reactions to selective cyclooxygenase-2 (COX-2) inhibitors are rare and they are typically well tolerated as alternative agents.

Occupational Asthma Management

Susan M. Tarlo, MD, BS, FRCPC — Thu, 19 Dec 2024 00:00:00 +0000

Occupational asthma is defined as asthma that is caused by work exposures, accounting for approximately 10-15% of all new-onset adult asthma. Typically, this is a new-onset of asthma in workers with no previous history of asthma. However, the diagnosis may also be made in individuals who had previous childhood asthma that cleared, then recurred as an adult due to work exposure. In contrast, work-exacerbated asthma is defined as asthma that is exacerbated but not caused by work exposures.

Occupational asthma can be caused by different mechanisms (Figure 1). It is most often due to a workplace sensitizer, which is a high- or low-molecular weight agent that causes asthma from an immunologic response. Asthma symptoms do not occur on the first exposure. Instead, they require a period ranging from days to years for sensitization. Once sensitized, subsequent exposures, even to very low levels of exposure, will trigger asthma. When this response is due to high-molecular weight sensitizers, which are typically proteins or glycoproteins, it is associated with specific IgE antibodies. In addition, specific IgE-antibodies are also associated with the response to some low molecular-weight sensitizers (chemical sensitizers) such as complex platinum salts and other metal salts. However, for most low-molecular weight sensitizers, the immune mechanism is unclear.

Treatment and Management of Chronic Cough in Children

Tristan Henry, MBBS, Anya McLaren, MD, MSc, FRCPC — Thu, 19 Dec 2024 00:00:00 +0000

Chronic cough (CC) in children is common and most often post-viral in nature. CC in children should be comprehensively evaluated and the underlying etiology treated to prevent irreversible lung damage. Refractory chronic cough (RCC) is proposed as a distinct clinical entity in children, which is defined by a persistent cough that does not resolve after comprehensive evaluation and adherence to systematic, guideline-based treatments. RCC may involve a heightened cough reflex sensitivity or altered neural regulation influenced by genetic, environmental, or immunologic factors. This review focuses on the definition, diagnostic approach, and evidence-based management of pediatric RCC, emphasizing the need for a multidisciplinary approach and highlighting research gaps for future targeted therapies.

Pearls from the 2024 European Respiratory Congress

Manali Mukherjee, MD — Thu, 19 Dec 2024 00:00:00 +0000

The European Respiratory Congress 2024, held from September 7th to 11th, 2024, in Vienna, Austria, featured several presentations on airway diseases, interstitial lung diseases, bronchiectasis, and critical care, with a focus on emerging therapies, particularly on asthma and chronic obstructive pulmonary disease (COPD).

At-home Management of Food-induced Anaphylaxis

Anne K. Ellis, MD, MSc, FRCPC — Thu, 19 Dec 2024 00:00:00 +0000

Anaphylaxis is an acute, potentially life-threatening, systemic reaction characterized by the involvement of two or more body systems. The National Institute of Allergy and Infectious Diseases and Food Allergy and Anaphylaxis Network (NIAID/FAAN) have well-established criteria for the clinical definition of anaphylaxis. Anaphylaxis is a severe allergic reaction that occurs suddenly after contact with an allergy-causing substance (e.g., peanuts), insect venom or medications (e.g., antibiotics). Anaphylaxis criteria include an acute onset of symptoms (within minutes to several hours) involving the skin, mucosal tissue, or both, which may present with generalized hives, pruritus or flushing, or swollen lips, tongue, and uvula. In addition, one or more of the following must be present: respiratory compromise, reduced blood pressure, or associated symptoms of end-organ dysfunction. Anaphylaxis results in a sudden release of mediators, including, but not limited to, histamine from activated mast cells and basophils following the cross-linking of specific immunoglobulin E. Together with downstream mediators, such as prostaglandin D2, platelet activating factor, and leukotrienes, this reaction manifests clinically through peripheral vasodilation, bronchoconstriction, and increased vascular permeability, presenting as a multi-organ emergency requiring immediate intervention.

It is estimated that up to 5% of the population has experienced anaphylaxis, although fatality rates are very low at approximately 0.3% and occur most commonly with drug-induced anaphylaxis. Older age, often consistent with pre-existing comorbidities, and delayed epinephrine administration, pose the most significant risk factors for anaphylaxis fatality. While the global rates of anaphylaxis appear to be on the rise, case fatalities fortunately do not seem to follow this trend.