Systemic and oral implications of long COVID

Key takeaways

Long COVID is a recognized disability with symptoms lasting 3+ months post-infection, affecting millions globally—including up to 10 million Americans.
Common symptoms include fatigue, brain fog, POTS, anxiety, and oral issues like ulcers, mycosis, and taste loss.
Oral health impact includes lesions, dry mouth, and increased caries risk—requiring careful evaluation and documentation by dental professionals.
Dental care adaptations include shorter visits, special positioning, infection control, and coordination with medical providers.
There’s a critical need for research and education on dental management of long COVID due to limited existing guidelines.

The medical/dental community is well aware of COVID-19 symptoms and treatment, but much less is known about long COVID. In July of 2021, long COVID was identified as a disability under the American Disabilities Act by the US government.¹ With this classification, clinicians need guidance on signs, symptoms, and treatment of the systemic and oral manifestations of long COVID.

History of COVID-19

In 2019, the world faced an outbreak of SARS-CoV-2.² In March of 2020, the World Health Organization recognized it as a pandemic.² SARS-CoV-2 became known as COVID-19. In April 2024, Worldometer’s coronavirus tracker calculated over 111,000,000 COVID-19 cases in the United States, with approximately 1.1 million deaths. Worldwide the death toll has reached about 7 million.³

Systemic symptoms of COVID-19 include fever, runny nose, nasal congestion, anosmia (loss of smell), dysgeusia (loss of taste), hypogeusia (disordered taste), diarrhea, nausea/vomiting, respiratory distress, fatigue, ocular symptoms (conjunctival secretions), and abdominal pain. Skin lesions include psoriasis, atopic dermatitis, and mucosal skin lesions in the nose and around the oral cavity.² The oral symptoms include herpes simplex outbreaks, candidiasis, geographic tongue, necrotic ulcerations, aphthous-like ulcers, hemorrhagic ulcerations, reddish macules, white hairy tongue, erythematous surfaces, petechiae, pustular enanthema, and bulla.²

Long COVID or post-COVID-19 syndrome

After the initial outbreak and rise of COVID-19, some individuals continue to experience prolonged symptoms related to the virus. Long COVID or post-COVID-19 syndrome (PCS) is defined by the Centers for Disease Control and Prevention as an “ongoing chronic condition that is present for at least three months after the SARS-CoV-2 infection.”⁴ The CDC reports that women, Hispanic and Latino populations, those hospitalized due to severe COVID-19, the elderly, and the unvaccinated are more likely to suffer from this lingering condition.⁴ Those with underlying health conditions are more prone to the disease, such as those with obesity and respiratory disease.⁵ While some groups are more susceptible to this chronic condition, anyone infected with the initial acute COVID-19 infection, including children, can be burdened by this problem.⁴ Globally, the incidence of long COVID was estimated to be around 400 million individuals.⁶ According to the American Academy of Physical Medicine and Rehabilitation, three to 10 million Americans are experiencing symptoms of long COVID.⁷

Systemic and psychosocial manifestations of long COVID

Systemic symptoms of long COVID include postexertional malaise, fatigue, dyspnea, brain fog, dizziness, gastrointestinal symptoms, heart palpitations, thirst, chronic cough, chest pain, cognitive impairments, joint and muscle discomfort, postural orthostatic tachycardia syndrome, and continued loss of smell.⁸ Eric Herman, MD, at Oregon Health and Science University, described these varied symptoms as a “confusing process” and “new territory for people to manage” (E. Herman, personal communication, December 10, 2024).

Psychological manifestations include anxiety, depression, mood swings, increased hopelessness, sleep issues, and brain fog.⁵ Patients have reported difficulty in receiving care or feeling that their health problems are being dismissed.⁹ A patient, who prefers to be anonymous, diagnosed with long COVID as manifested by postural orthostatic tachycardia syndrome (POTS) and fatigue, reported this condition as being a “frustrating disease.”

Oral manifestations of long COVID

Clinical case studies by Rafalowicz et al. reported oral discoloration, ulceration, hemorrhagic changes in mucosa, mycosis on the tongue, aphthous-like lesions, and atrophic cheilitis.¹⁰ These lesions were localized on the palate, tongue, and salivary glands. Loss of taste and smell for months after the acute infection were also found. This may affect dietary choices, contributing to nutritional imbalances or deficiencies affecting periodontal disease or caries risk.⁸

It is thought that changes in the oral cavity are likely due to immunosuppression caused by the virus or dysfunction of the immune system, stress, poor oral hygiene, opportunistic infections, vasculitis, reinfection, or multiorgan disorders. Changes in the mouth due to long COVID may persist for two to six months after the infection but can also disappear spontaneously or within three weeks of treatment.¹⁰

Oral management of long COVID

Due to the varied nature of the disease, a symptoms-based approach is recommended. Oral health-care providers play a crucial role in monitoring and identifying patient concerns. Cooperation and management with the patient’s medical team is necessary to address all factors considered. Treatment should be provided after consideration of the patient’s ability to tolerate given procedures.⁵ Clinicians should consider the following:

Oral cancer screening. This patient population is at risk of developing viral, fungal, or bacterial infections.

Documentation and monitoring of oral lesions. Discuss the following with patients:

When were you last diagnosed with COVID-19?
When did the recent symptoms start?
Has the severity of the symptoms changed over time?
Does anything make it better or worse?
Provide adequate descriptions of all oral lesions.

Clinical treatment

Patient medications and effects on the procedure: assess the use of anticoagulants and glucocorticosteroids, which may pose risks/complications of bleeding, infection, changes in mood, increased blood sugar, and adrenal insufficiency.
Postural orthostatic tachycardia syndrome (POTS)
Chair positioning
Shortened appointments: due to malaise and one’s ability to withstand treatment
Stress-reduction strategies due to unpredictable changes in blood pressure and heart rate

Infection control to include preprocedural mouth rinse, aspirating systems equipped with HEPA filters, and disposable PPE

Thorough OH instructions. Collaborative approach with medical personnel adopting a whole-
person approach

Conclusion

Providing dental personnel with the knowledge of long COVID signs and symptoms, as well as treatment options, will help providers deliver optimal and comprehensive care for patients. Currently, research is limited and lacks high-quality evidence-based guidelines for medical and dental personnel. More research is needed in this area. In the meantime, health-care providers should make every effort to offer treatment options and referrals. Individuals experiencing this condition should urge health-care providers to show compassion for those struggling with the symptoms and aftereffects of long COVID.

Editor's note: This article appeared in the June 2025 print edition of RDH magazine. Dental hygienists in North America are eligible for a complimentary print subscription. Sign up here.

References

Patton LL. Long-Covid and the practice of oral medicine. Oral Surg Oral Med Oral Pathol Oral Radiol. 2021;133(2):125-128. doi:1016/j.oooo.2021.10.025
Rusu LC, Ardelean LC, Tigmeanu CV, Matichescu A, Sauciur I, Bratu EA. Covid-19 and its repercussions on oral health: a review. Medicina (Kaunas). 2021;57(11):1189. doi:10.3390/medicina57111189
United States COVID – coronavirus statistics. Worldometer. 2024. Accessed February 19, 2025. https://www.worldometers.info/coronavirus/country/us/
Long COVID basics. Centers for Disease Control and Prevention. February 3, 2025. https://www.cdc.gov/covid/long-term-effects/index.html
France K, Glick M. Long COVID and oral health care considerations. J Am Dent Assoc. 2022;153(2):167-174. doi:10.1016/j.adaj.2021.08.007
Al-Aly Z, Davis H, McCorkell L, et al. Long COVID science, research and policy. Nat Med. 2024;30(8):2148-2164. doi:10.1038/s41591-024-03173-6
PM&R’s response to COVID-19. American Academy of Physical Medicine and Rehabilitation. https://www.aapmr.org/advocacy/current-priorities/long-covid-pasc/call-to-action
Solomon SM, Pasarin L, Sufaru IG, et al. Considerations on the effects of taste changes caused by long-covid on nutrition and oral health. Romanian J Oral Rehabil. 2023;15(3):284-295.
Long COVID: lasting effects of COVID-19. Mayo Clinic. August 23, 2024. https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-long-term-effects/art-20490351
Rafałowicz B, Wagner L, Rafałowicz J. Long COVID oral cavity symptoms based on selected clinical cases. Eur J Dent. 2022;16(2):458-463. doi:10.1055/s-0041-1739445