Dennis K. Ledford; Richard F. Lockey


Curr Opin Allergy Clin Immunol. 2013;13(1):78-86. 

In This Article

Clinical Importance of Comorbidities

The effectiveness of asthma treatment as summarized in a variety of guidelines makes asthma management generally satisfactory. However, surveys show in a variety of settings that achieving optimal asthma control varies from 30 to 70%.[1,2] Asthma is prone to exacerbations that result in an inherent unpredictability, which can be minimized but not eliminated. However, individuals who do not respond or respond inconsistently to treatment often have a comorbidity. These comorbidities may result in misdiagnosis, misinterpretation of symptoms, aggravation of one or both diseases, or decreased adherence.[3,4] Recognition of these comorbidities facilitates more appropriate therapy or reduction of potentially risky therapies, such as systemic corticosteroids.

Comorbidities increase the likelihood of poorly controlled asthma as evidenced by a relatively small study by ten Brinke et al.[5] Individuals with a confirmed diagnosis of asthma and frequent exacerbations were surveyed for coexisting conditions. The association was calculated for a specific comorbidity and the likelihood of more frequent asthma exacerbations. One hundred and thirty-six individuals completed the survey. The odds ratio (OR) of experiencing an asthma exacerbation was increased 10.8-fold by depression, 4.9-fold by GERD, 3.7-fold by severe sinus disease, and 3.4-fold by obstructive sleep apnea.

Most of the data in the medical literature supporting a relationship of asthma with other comorbidities are based upon cross-sectional surveys or small cohorts. These data cannot confirm causal relationships or show the direction of any observed or suspected relationship. Thus, for the most part, the discussion in this article reviews possibilities rather than confirmed relationships.

The order of the comorbidities is based upon the authors' experience and their opinion as to the relative frequency of occurrence as well as the available medical literature to support the association.[3] Numerous potential comorbidities with asthma will not be discussed in this review but are listed at the top of the next page. In addition, the clinician should consider alternative diagnoses when asthma control is elusive. Bronchial and pulmonary diseases likely to be confused with asthma are provided in Table 1 . Diseases, conditions, or medications that result in shortness of breath or cough are listed below.

  1. Anemia

  2. Deconditioning

  3. Heart disease

  4. Medications (angiotensin converting enzyme inhibitor)

  5. Pulmonary embolus

  6. Pulmonary hypertension

  7. Thyroid compression of trachea (retrosternal thyroid)

  8. Vascular ring

  9. Vasculitis

Comorbidities of asthma are listed below. Some of the comorbidities overlap, for example, allergic rhinitis and rhinitis and respiratory infection or 'bronchitis and bronchopneumonia'. The list is based upon health administration data of approximately 12 million children and adults, 1.5 million of whom had asthma.

Comorbidities of asthma are as follows:[6]

  1. Allergic rhinitis

  2. Atherosclerotic cardiac disease and circulatory disorders

  3. Bronchitis and bronchopneumonia

  4. Connective tissue diseases

  5. Dermatologic conditions (eczema)

  6. Gastroesophageal reflux (GERD) and other gastrointestinal disease

  7. Immunologic and hematologic diseases

  8. Metabolic disorders

  9. Neurologic disorders

  10. Obesity

  11. Obstructive lung disease (COPD)

  12. Paradoxical vocal fold movement [vocal cord dysfunction (VCD)]

  13. Pregnancy

  14. Psychologic disease (anxiety, depression, behavioral disorders)

  15. Respiratory infection

  16. Rhinitis and rhinosinusitis