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COVID-19 Considerations

Pay Attention to the Zebra

Zuzelo, Patti Rager EdD, RN, ACNS-BC, ANP-BC, ANEF, FAAN

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doi: 10.1097/HNP.0000000000000423
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The lore of differential diagnosis often includes the admonition, “If you hear hoof beats behind you, think horses, not zebras.” The intended instruction is meant to convey to students and novice health care providers that the wise clinician avoids attributing case presentations to exotic pathology and first considers more likely, commonplace suspects. Novel coronavirus disease 2019 (COVID-19) is presenting across the United States and the world as a pandemic with varying spread and intensity. Health care providers are often asked not only by patients but also by neighbors, family members, and acquaintances about presenting signs and symptoms, aberrant illness trajectories, and upcoming therapies. Health care professionals are obliged to provide evidence-based instruction to those in need of such information and certainly need to be aware of the most commonly experienced signs and symptoms; however, zebra-like COVID-19 presentations are also important, particularly given the newness of this particular infecting organism and the associated unknowns of its effects.

The Centers for Disease Control and Prevention provides excellent information about COVID-19 that is written in plain language.1 Readers are cautioned that signs and symptoms may present within 2 to 14 days of exposure and may include fever, chills, cough, shortness of breath, tiredness, body aches, headache, sore throat, congestion, runny nose, absent sensation of smell or taste, and gastrointestinal distress, which are noted as possible COVID-19 manifestations.1 Other published resources pose case study information that support the association between COVID-19 and clinical presentations that might go unrecognized, given that they are not recognized as classic or typical indicators.

Anecdotal reports suggest that significant hair loss, telogen effluvium, may be associated with COVID-19.2 This temporary form of hair loss is associated with dramatic stress, physical or emotional, including high fevers and significant weight loss. This condition is also associated with medications, childbirth, and thyroid disorders.3 Telogen effluvium is typically triggered by a stressor event that occurs about 12 to 16 weeks prior to the actual hair loss. The usual pattern is for the hair loss to persist for 3 to 6 months, followed by total resolution, otherwise known as acute telogen effluvium. The hair volume is notably reduced, and women with longer hair may notice a thinning pony tail or hair bunch while other men or women may see a widening part as well as hair falling out in clumps or large batches as compared with usual expected shedding.3 Health care professionals should recognize the possibility of this condition in association with COVID-19 so that accurate education and support may be provided to the affected individual.

Loss of taste and smell is not commonly assessed in clinical practice and may be inadvertently missed by the clinician during patient evaluation unless the patient notices the change or the care provider purposefully asks about these changes. Anosmia, lost ability to smell scents, is associated with sinus infections, nasal inflammation, aging, head trauma, genetic conditions, and neurodegenerative conditions as well as other circumstances; however, acute loss of smell should be considered as a possible indication of COVID-19. Early study findings suggest that COVID-19–associated anosmia is present in 30% to 98% of hospitalized people.4 A lost sense of smell is difficult to assess, given its highly variable nature and a lack of objective measures.4 It may also be that a sudden loss of taste is related to anosmia, given the important contribution of smell to taste.5 If anosmia is associated with respiratory symptoms, fever, muscle aches, or other potential COVID-19 manifestations, the affected individual should self-quarantine and be tested.

Sudden, unusual skin changes may also signify COVID-19 infection. Purple and red bumps on toes, also referred to as COVID toes, are increasingly noted by health care providers as potential indicators of COVID-19 infection.6 These lesions are similar to chilblains but are typically not presenting in people with a history of such. Chilblains occur in response to repeated exposure to cold air.7 The etiology is unknown but is likely related to an unusual response to cold. International reports describe COVID toes as additionally affecting soles and heels and more typically presenting in younger people.6 Published literature describes these lesions as self-limited and their initial presence may be during an active or mild infection or several weeks following the acute event.6

The World Wide Web provides many images of COVID toes and chilblains. Symptoms include burning, itching, and exquisite sensitivity to touch. Some report that antihistamines, anti-inflammatories, and ice were useful therapies to reduce discomfort,6 and a quick online search of various reputable layperson sources support that the lesions are limited to a few weeksʼ duration. The typical explanation for this condition is that it is an inflammatory reaction to the virus. An international registry initiated by the American Academy of Dermatology is now tracking the dermatologic manifestations of COVID-19.8 Toe cases comprise approximately half of all reports to this database.6

Holistic care providers should ask questions about whether such lesions have occurred and, if so, encourage COVID-19 testing and self-quarantine. Given the benign clinical course of COVID toes, this particular sign does not warrant emergency evaluation. The wiser course of action is to educate the individual as to the need to avoid unnecessarily exposing others to COVID-19 with the caveat that medical evaluation is necessary if concerning signs or symptoms of COVID manifest, including shortness of breath.

Some people with more severe COVID 19 infections may experience eye problems, including but not limited to enlarged red blood vessels, eyelid swelling, and manifestations of conjunctivitis. Affected individuals may report light sensitivity and describe tearing, drainage, and the sensation of a foreign body in the eye.9,10 If there is no identifiable trigger for these symptoms, COVID-19 may be suspected. Nurses and other providers need to be wary of infection transmission not only via mucous membrane or drainage contact but also related to the close proximity required for eye examination. The number of COVID-19–related ocular cases is reportedly small,10 but providers should be aware of the possibility of such manifestations and respond appropriately within recommended standards of care.

The SARS-CoV-2 virus or COVID 19 is new and novel, and there are knowledge gaps about its presentation, short-term effects, and long-term sequelae that will undoubtedly be corrected with time. Classic symptoms of COVID-19 are largely understood to include fever, cough, shortness of breath, fatigue, and muscle aches. Other manifestations are also associated with this infection in varying degrees, and these less appreciated signs and symptoms may be first detected by the astute clinician who is open to the possibility of a “zebra sighting” while staying focused on more likely sign and symptom etiologies. As data are collected and analyzed, an accurate composite picture of COVID-19 will emerge. In the meantime, nurses and other professionals should remain open to the possibility of unique and unusual COVID-19 presentations.


1. Centers for Disease Control and Prevention. Symptoms of coronavirus. Updated May 13, 2020. Accessed August 3, 2020.
2. Clopton J. Hair loss. An unexpected misery for many. Published July 29, 2020. Accessed August 3, 2020.
3. Liyanage D, Sinclair R. Telogen effluvium. Cosmetics. 2016;3(2). Accessed August 3, 2020.
4. Kay L. Why COVID-19 makes people lose their sense of smell. Scientific American. Published June 13, 2020. Accessed August 3, 2020.
5. Penn Medicine. How COVID-19 can impact your sense of smell. Accessed August 3, 2020.
6. Rabin RC. What is COVID toe? Maybe a strange sign of coronavirus infection. The New York Times. Updated May 5, 2020. Accessed August 4, 2020.
7. Mayo Clinic. Chilblains. Published November 27, 2018. Accessed August 4, 2020.
8. American Academy of Dermatology. COVID 19 Dermatology Registry. Published 2020. Accessed August 4, 2020.
9. Marshall WF. Unusual coronavirus (COVID-19) symptoms. What are they? Published June 30, 2020. Accessed August 4, 2020.
10. Hu K, Patel J, Patel BC. Ophthalmic Manifestations of Coronavirus (COVID-19). Treasure Island, FL: StatPearls Publishing; 2020. Accessed August 4, 2020.
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