Dry cough, congestion, drainage and limited sense of smell are all overlapping, common symptoms of seasonal allergies and COVID-19, yet less-common symptoms shared between the two include fatigue, body aches and pains, and shortness of breath (especially if asthmatic). Conjunctivitis may also fall into this category, but neither the CDC nor World Health Organization currently list it as a major symptom of COVID-19. That said, a British Journal of Ophthalmology report recently detailed the ocular complications of SARS-CoV-2, including viral conjunctivitis.
"Allergy patients frequently experience an overlap of signs and symptoms," says Renee Reeder, O.D., department chair of clinical affairs at the University of Pikeville Kentucky College of Optometry. "Patients presenting with ocular allergy will often complain of [sneezing], itchy eyes, nose and throat. Some will experience Hay fever with a low-grade fever usually under 100.0 degrees. Patients may have a bluish hue to the lids, evidence of mild angioedema and often referred to as an 'allergic shiner.'"
But that's in contrast to COVID-19 patients: fevers of 100.4 or higher, dry cough, difficulty breathing, fatigue, muscle aches and chills, loss of smell or taste, and gastrointestinal issues, Dr. Reeder notes. While itchy eyes may be associated with conjunctivitis, foreign body sensation is more common with viral forms of conjunctivitis, she says.
Doctors of optometry with additional training in ear, nose and throat evaluation may also look for a few additional signs. Whereas patients suffering from allergies will often have boggy, bluish nasal mucosa and fluid visible behind their ear drum-post-nasal drainage is a hallmark of allergy-viral patients will often have greater injection of the nasal mucosa and increased lymphadenopathy, Dr. Reeder says.
Nonetheless, doctors of optometry should take extra precautions in situations that present the potential for COVID-19 spread.
"Anecdotal evidence does suggest that a small number of patients who have COVID-19 conjunctivitis will have low levels of the virus in their tears; the virus has not been isolated from COVID patients without conjunctivitis," Dr. Reeder points out. "Additional articles suggest that conjunctivitis is more likely in those patients with more advanced disease."
Sections of this article have been reviewed by the AOA COVID-19 Evidence-based Optometry Response subcommittee.