COVID-19 Allergies

Spring is here! Differentiating COVID-19 from seasonal allergies

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Spring is finally in the air – but for many of our patients, that may mean the start of their allergy season. And if that is not enough, like many of us, they are more anxious than ever that they might have been exposed to or contracted SARS-CoV-2 / COVID-19.

So when they develop a runny nose and dry cough in the coming weeks, it can be understandably disconcerting. If they have asthma and there is associated shortness of breath, it might really start to ring alarms.

So is this just their allergies or is this COVID-19? How do I tell the difference?

First, there are symptoms that are unique to infections like COVID-19 that don’t occur with environmental allergies. The first, and most important, is fever. “Hay fever” sure sounds like fever should be a symptom, but true fevers are not a feature of allergies and always suggest that something else is going on. Fatigue, often profound, is described in 23-70% of COVID patients and 11-35% will report aches and pains (myalgias) – these are more in keeping with a viral illness rather than allergies. Sore throat and GI symptoms including diarrhea are uncommon though possible in COVID-19, but are not allergic symptoms.​1–3​

There are also symptoms classic to environmental allergies that are quite rare in COVID-19 patients. Conjunctivitis (red eye) symptoms are common in allergy sufferers but have only rarely been described in COVID-19 patients.​2​ Also, while rhinorrhea (runny nose) and even anosmia (loss of smell) are interestingly described in both, prominent nasal congestion is much more common in allergic rhinoconjunctivitis than with COVID-19.​4​

Will treating their allergies or asthma increase their risk of COVID-19 and associated complications?

From a rhinitis perspective, second generation intranasal corticosteroids (e.g. fluticasone, mometasone, ciclesonide) are minimally absorbed and should not compromise one’s ability to fight the infection. The Global Initiative for Asthma (GINA) consortium recommends continuing intranasal corticosteroids that are prescribed for rhinitis.​5​

Definitive data on asthma in COVID-19 is scarce, but extrapolating from other respiratory viruses, patients with moderate to severe asthma may be at higher risk of poor outcomes. This has led to the CDC specifically listing moderate to severe asthmatics as ‘higher risk’.​6​ Intuitively, it makes sense to have asthmatics as well-controlled as possible during this pandemic.

Supporting this, most major Allergy Societies and GINA have recommended patients continue their regular medications. This includes corticosteroid inhalers, anti-IgE and anti-eosinophil biologics, and even oral steroids if required.​7​

For patients who get COVID-19, medications should be continued, but inhaled medications should be given by regular inhalers (with spacers if required) rather than via nebulizer to avoid aerosolizing the virus and infecting others. If symptoms progress to an asthma exacerbation, this should be treated using the regular algorithm, again avoiding nebulized bronchodilators.​5​

To improve patient (and physician) understanding of the difference between COVID-19 and allergy symptoms, and to summarize treatment decisions, the CanadiEM Infographics Team has created an infographic below. It can be downloaded for dissemination and printing here.

Stay healthy, everyone!

Allergies vs COVID-19

This post was copyedited and reviewed by Patrick Boreskie.

  1. 1.
    Wang D, Hu B, Hu C, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus–Infected Pneumonia in Wuhan, China. JAMA. March 2020:1061. doi:10.1001/jama.2020.1585
  2. 2.
    Guan W, Ni Z, Hu Y, et al. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med. February 2020. doi:10.1056/nejmoa2002032
  3. 3.
    Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. The Lancet. March 2020:1054-1062. doi:10.1016/s0140-6736(20)30566-3
  4. 4.
    Giacomelli A, Pezzati L, Conti F, et al. Self-reported olfactory and taste disorders in SARS-CoV-2 patients: a cross-sectional study. Clinical Infectious Diseases. March 2020. doi:10.1093/cid/ciaa330
  5. 5.
    COVID-19: GINA Answers To Frequently Asked Questions on Asthma Management. Global Initiative for Asthma. Published March 25, 2020. Accessed April 1, 2020.
  6. 6.
    COVID-19 – People who are at higher risk. Center for Disease Control. Published April 2, 2020. Accessed April 3, 2020.
  7. 7.
    Recommendations for Inhaled Asthma Controller Medications. Global Initiative for Asthma. Published March 19, 2020. Accessed April 1, 2020.

David Fahmy

Dr. David Fahmy is a staff Clinical Immunology and Allergy (CIA) Physician with practices in Hamilton and Toronto, Ontario. He is an Assistant Clinical Professor in the CIA Division at McMaster University. There, he serves as the Education Coordinator for the training program and serves as the CBME lead and Competence Committee chair. He recently completed his Masters of Science in Health Sciences Education at McMaster University where he focused on adaptations and application of CBME in smaller programs.

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