Rachel Georgopoulos, MD, John H. Krouse, MD, PhD and Elina Toskala, MD, PhD∗elina.toskala@tuhs.temple.edu,     Department of Otolaryngology, Temple University Health System, 3509 North Broad Street, Philadelphia, PA 19140-4105, USA

∗Corresponding author.

Consideration of the unified airway model when managing patients with rhinitis and or asthma allows a more comprehensive care plan and therefore improved patient outcomes. Asthma is linked to rhinitis both epidemiologically and biologically, and this association is even stronger in individuals with atopy. Rhinitis is not only associated with but is a risk factor for the development of asthma. Management of rhinitis improves asthma control. Early and aggressive treatment of allergic rhinitis may prevent the development of asthma. In patients with allergic rhinitis that is not sufficiently controlled by allergy medication, allergen-directed immunotherapy should be considered.

Keywords

Asthma

Rhinitis

Allergy

Immunology

Key points

Introduction

Although rhinitis and asthma are frequently comorbid conditions, physicians managing patients with rhinitis and or rhinosinusitis have traditionally not taken part in the diagnosis or management of asthma. Rhinitis, sinusitis, and asthma are linked both epidemiologically and pathophysiologically and thus the nose through the paranasal sinuses to the distal bronchioles should not be thought of as separate entities but rather constituents of 1 functional unit. This unit is referred to as the unified airway model.1–3 Rhinitis is not only associated with but is a risk factor for the development of asthma.4–11 Although both allergic and nonallergic forms of rhinitis are associated with asthma, the association between asthma and allergic rhinitis (AR) is even stronger.4,11 The use of allergen-directed immunotherapy in young children with allergic rhinitis has been shown to prevent the development of asthma in later life.12–14 Irritants and allergens presented at one portion of the airway have distal effects. It is thought that the upper and lower airways communicate through a complex interaction of inflammatory mediators and the autonomic system. Furthermore, disease severities in rhinitis and asthma often parallel each other.4,15 Adequate treatment of allergic rhinitis can allow better asthma control and, in some situations, may even prevent the development of asthma.16–20 With the substantial evidence to support the link between upper and lower airway disease it is imperative that physicians who manage patients with rhinitis and sinusitis become familiar with the diagnosis and management of asthma.

AR and asthma defined

AR is defined as a symptomatic immunoglobulin E (IgE)–mediated inflammation of the nasal mucosa.9 Symptoms of rhinitis are reversible and include nasal congestion/obstruction, rhinorrhea, sneezing, pruritus, postnasal drip, chronic cough, throat clearing, and conjunctivitis.9,21 Rhinitis is categorized, based on duration of symptoms and by the disease’s impact on quality of life, as intermittent or persistent mild or moderate to severe (Table 1).9

Asthma is a chronic inflammatory disorder of the airways that results in reversible airway obstruction and bronchial hyperresponsiveness (BHR) to a variety of stimuli. Inflammatory mediators and mainly mast cells, eosinophils, T lymphocytes, neutrophils, and epithelial cells are known to play an important role in this process. In advanced cases, airway remodeling can occur, with irreversible injury to the pulmonary mucosa. The airway inflammation and subsequent airway obstruction experienced by these individuals can result in symptoms of wheezing, breathlessness, chest tightness, and coughing.22,23

Although the focus of asthma pathophysiology was once on the hyperresponsiveness of the airways, it is now known that inflammation is the driving mechanism, with the increased bronchial reactivity being caused by this inflammatory state. This concept is important to understanding the pathophysiology and treatment of asthmatics.

Epidemiology