‘Long Haulers’: A Long Road Back to Oral and Systemic Health

‘Long Haulers’: A Long Road Back to Oral and Systemic Health

The COVID-19 pandemic was announced in March 2020,1WHO. Coronavirus disease (COVID-19) Weekly Epidemiological Update and Weekly Operational Update. Available at: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports. and the health and societal impacts quickly became apparent. Signs and symptoms included fever, fatigue, loss of taste, loss of smell, headache, sore throat, dry cough, shortness of breath, myalgia, gastrointestinal upsets, chest pain, less frequent and more severe manifestations.2Hastie CE, Lowe DJ, McAuley A et al. Outcomes among confirmed cases and a matched comparison group in the Long-COVID in Scotland study. Nat Commun 2022;13(1):5663. doi: 10.1038/s41467-022-33415-5.^,3Agyeman AA, Chin KL, Landersdorfer CB et al. Smell and Taste Dysfunction in Patients With COVID-19: A Systematic Review and Meta-analysis. Mayo Clin Proc 2020;95(8):1621-31. doi:10.1016/j.mayocp.2020.05.030.^,4Rothan HA, Byrareddy SN. The epidemiology and pathogenesis of coronavirus disease (COVID-19) outbreak. J Autoimmun 2020; doi:10.1016/j.jaut.2020.102433. It is now well-recognized that, in some patients, symptoms may continue or re-emerge over longer periods – leading to these individuals being referred to as ‘long haulers’ and the condition being referred to as Long-COVID (also known as Long-haul COVID, Post-COVID-19 condition and Post-COVID Syndrome).5Soriano JB, Murthy S, Marshall JC et al. A clinical case definition of post-COVID-19 condition by a Delphi consensus. Lancet Infect Dis 2022;22(4):e102-7. doi: 10.1016/S1473-3099(21)00703-9. This condition can be broadly defined as signs, symptoms, and conditions that continue or develop after acute COVID-19 infection.6Centers for Disease Control and Prevention. COVID-19. Long COVID or Post-COVID Conditions. https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects/index.html. In this article, we’ll look at the prevalence of Long-COVID, factors placing individuals at risk, oral and systemic signs and symptoms, and some of the implications for the care of long haulers.

Prevalence of Long-COVID

In a review of publications from December 2019 to September 2021, the prevalence of Long-COVID ranged from 30% to 60%.7Malkova A, Kudryavtsev I, Starshinova A et al. Post COVID-19 Syndrome in Patients with Asymptomatic/Mild Form. Pathogens 2021;10(11):1408. doi: 10.3390/pathogens10111408. Similarly, in a prospective study with almost 600 individuals, 6 months after infection with SARS-CoV-2, 40.2% had Long-COVID.8Peghin M, Palese A, Venturini M et al. Post-COVID-19 symptoms 6 months after acute infection among hospitalized and non-hospitalized patients. Clin Microbiol Infect 2021;27(10):1507-13. doi: 10.1016/j.cmi.2021.05.033. Among almost 300 participants who entered another study while initially infected, and completed a survey at the one-year mark, 59.5% reported at least 1 symptom (median 6 symptoms).9Fischer A, Zhang L, Elbéji A et al. Long COVID Symptomatology After 12 Months and Its Impact on Quality of Life According to Initial Coronavirus Disease 2019 Disease Severity. Open Forum Infect Dis 2022;9(8):ofac397. doi:10.1093/ofid/ofac397. In a Scottish prospective study with subjects with confirmed SARS-CoV-2 infections, serial questionnaires at 6,12 and 18 months were completed by almost 4,000 individuals, with 47% and 8%, respectively, indicating partial and full recovery by the first follow-up, and little change thereafter.2Hastie CE, Lowe DJ, McAuley A et al. Outcomes among confirmed cases and a matched comparison group in the Long-COVID in Scotland study. Nat Commun 2022;13(1):5663. doi: 10.1038/s41467-022-33415-5.

Risk Factors for Long-COVID

Risk factors include the symptomology and severity of COVID-19 infections, and other patient-level factors.

Initial and Subsequent Infections
Symptomatic initial infection with SARS-CoV-2 carries a significantly greater risk for Long-COVID compared to asymptomatic infection.9Fischer A, Zhang L, Elbéji A et al. Long COVID Symptomatology After 12 Months and Its Impact on Quality of Life According to Initial Coronavirus Disease 2019 Disease Severity. Open Forum Infect Dis 2022;9(8):ofac397. doi:10.1093/ofid/ofac397.^,10Adler L, Gazit S, Pinto Y et al. Long-COVID in patients with a history of mild or asymptomatic SARS-CoV-2 infection: a Nationwide Cohort Study. Scand J Prim Health Care 2022;40(3):342-9. doi: 10.1080/02813432.2022.2139480.^,11Ma Y, Deng J, Liu Q et al. Long-Term Consequences of Asymptomatic SARS-CoV-2 Infection: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health 2023;20(2):1613. doi: 10.3390/ijerph20021613. In one systematic review and meta-analysis it was concluded that asymptomatic individuals had an 80% lower risk for developing at least one symptom.11Ma Y, Deng J, Liu Q et al. Long-Term Consequences of Asymptomatic SARS-CoV-2 Infection: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health 2023;20(2):1613. doi: 10.3390/ijerph20021613. In another review, approximately 83% and 39% of symptomatic and asymptomatic individuals, respectively, experienced Long-COVID (p <0 .001).9Fischer A, Zhang L, Elbéji A et al. Long COVID Symptomatology After 12 Months and Its Impact on Quality of Life According to Initial Coronavirus Disease 2019 Disease Severity. Open Forum Infect Dis 2022;9(8):ofac397. doi:10.1093/ofid/ofac397. (Figure 1)

Among total symptomatic COVID-19 cases in a cohort study, 48.19% of the mild cases, and 66.54% of the moderate/severe cases developed at least one symptom of Long-COVID,10Adler L, Gazit S, Pinto Y et al. Long-COVID in patients with a history of mild or asymptomatic SARS-CoV-2 infection: a Nationwide Cohort Study. Scand J Prim Health Care 2022;40(3):342-9. doi: 10.1080/02813432.2022.2139480. and hospitalization with severe COVID-19 is recognized as a risk factor.2Hastie CE, Lowe DJ, McAuley A et al. Outcomes among confirmed cases and a matched comparison group in the Long-COVID in Scotland study. Nat Commun 2022;13(1):5663. doi: 10.1038/s41467-022-33415-5.^,12Trapani G, Verlato G, Bertino E et al. Long COVID-19 in children: an Italian cohort study. Ital J Pediatr 2022;48(1):83. doi: 10.1186/s13052-022-01282-x. Furthermore, individuals who experience multiple COVID-19 infections are at greater risk for cardiac, neurological and pulmonary complications.13Boufidou F, Medić S, Lampropoulou V et al. SARS-CoV-2 Reinfections and Long COVID in the Post-Omicron Phase of the Pandemic. Int J Mol Sci 2023;24(16):12962. doi: 10.3390/ijms241612962.

In a study conducted in Luxembourg, it was found that individuals with mild initial infections experienced milder Long-COVID and the least symptoms, and increased severity correlated with the most symptoms and severity of Long-COVID.14Fischer A, Badier N, Zhang L et al. Long COVID Classification: Findings from a Clustering Analysis in the Predi-COVID Cohort Study. Int J Environ Res Public Health 2022;19(23):16018. doi: 10.3390/ijerph192316018.

This condition also varies in children based on the initial infection.12Trapani G, Verlato G, Bertino E et al. Long COVID-19 in children: an Italian cohort study. Ital J Pediatr 2022;48(1):83. doi: 10.1186/s13052-022-01282-x.^,15Parums DV. Editorial: Long-Term Effects of Symptomatic and Asymptomatic SARS-CoV-2 Infection in Children and the Changing Pathogenesis of Common Childhood Viruses Driven by the COVID-19 Pandemic. Med Sci Monit 2022;28:e937927. doi: 10.12659/MSM.937927. In one study, 46.5% and 11.5% of children with symptomatic and asymptomatic initial infections, respectively, experienced Long-COVID and 58% of children who had been hospitalized with COVID-19.12Trapani G, Verlato G, Bertino E et al. Long COVID-19 in children: an Italian cohort study. Ital J Pediatr 2022;48(1):83. doi: 10.1186/s13052-022-01282-x. (Figure 2) In a second study, 21% of adults and 15% of children with asymptomatic COVID-19, respectively, developed at least one symptom of Long-COVID.10Adler L, Gazit S, Pinto Y et al. Long-COVID in patients with a history of mild or asymptomatic SARS-CoV-2 infection: a Nationwide Cohort Study. Scand J Prim Health Care 2022;40(3):342-9. doi: 10.1080/02813432.2022.2139480.

Other Patient-level Factors
Other reported risk factors include older age, being female, increased BMI, smoking, dyslipidemia, deprivation, respiratory disease, asthma, psychological distress (including depression) and poor overall health.2Hastie CE, Lowe DJ, McAuley A et al. Outcomes among confirmed cases and a matched comparison group in the Long-COVID in Scotland study. Nat Commun 2022;13(1):5663. doi: 10.1038/s41467-022-33415-5.^,7Malkova A, Kudryavtsev I, Starshinova A et al. Post COVID-19 Syndrome in Patients with Asymptomatic/Mild Form. Pathogens 2021;10(11):1408. doi: 10.3390/pathogens10111408.^,10Adler L, Gazit S, Pinto Y et al. Long-COVID in patients with a history of mild or asymptomatic SARS-CoV-2 infection: a Nationwide Cohort Study. Scand J Prim Health Care 2022;40(3):342-9. doi: 10.1080/02813432.2022.2139480.^,13Boufidou F, Medić S, Lampropoulou V et al. SARS-CoV-2 Reinfections and Long COVID in the Post-Omicron Phase of the Pandemic. Int J Mol Sci 2023;24(16):12962. doi: 10.3390/ijms241612962.^,14Fischer A, Badier N, Zhang L et al. Long COVID Classification: Findings from a Clustering Analysis in the Predi-COVID Cohort Study. Int J Environ Res Public Health 2022;19(23):16018. doi: 10.3390/ijerph192316018.^,16Jaramillo M, Thyvalikakath TP, Eckert G, Srinivasan M. Characteristics of Chemosensory Perception in Long COVID and COVID Reinfection. J Clin Med 2023;12(10):3598. doi: 10.3390/jcm12103598.^,17Thompson EJ, Williams DM, Walker AJ et al. Long COVID burden and risk factors in 10 UK longitudinal studies and electronic health records. Nat Commun 2022;13(1):3528. doi: 10.1038/s41467-022-30836-0.

Systemic Symptoms and Conditions

Common symptoms of Long-COVID include fatigue, cough, headache, shortness of breath, loss of taste, loss of smell, reduced cognitive function, neurological disorders and cardiovascular conditions such as tachycardia, arrythmias and heart failure.5Soriano JB, Murthy S, Marshall JC et al. A clinical case definition of post-COVID-19 condition by a Delphi consensus. Lancet Infect Dis 2022;22(4):e102-7. doi: 10.1016/S1473-3099(21)00703-9.^,7Malkova A, Kudryavtsev I, Starshinova A et al. Post COVID-19 Syndrome in Patients with Asymptomatic/Mild Form. Pathogens 2021;10(11):1408. doi: 10.3390/pathogens10111408.^,9Fischer A, Zhang L, Elbéji A et al. Long COVID Symptomatology After 12 Months and Its Impact on Quality of Life According to Initial Coronavirus Disease 2019 Disease Severity. Open Forum Infect Dis 2022;9(8):ofac397. doi:10.1093/ofid/ofac397.^,11Ma Y, Deng J, Liu Q et al. Long-Term Consequences of Asymptomatic SARS-CoV-2 Infection: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health 2023;20(2):1613. doi: 10.3390/ijerph20021613.^,18Ziauddeen N, Gurdasani D, O’Hara ME et al. Characteristics and impact of Long Covid: Findings from an online survey. PLoS ONE 2022;17:e0264331. In a large dataset analysis (2023), new-onset hypertension and heart failure, other cardiovascular disorders, and cerebrovascular disorders, were found to be more prevalent in patients with Long-COVID (from 30 days to 12 months post-infection) than in a control group.19Gallo A, Covino M, Lipari A et al. Increase in Chronic Medications and Polypharmacy-The Multifaceted Burden of COVID-19 Disease on Public Health Care. J Pers Med 2023;13(9):1321. doi: 10.3390/jpm13091321. Other manifestations include chest pain; gastrointestinal, metabolic, musculoskeletal, hematologic and renal conditions; increased risk for blood clots and thrombotic events; and mental health/psychiatric disorders.6Centers for Disease Control and Prevention. COVID-19. Long COVID or Post-COVID Conditions. https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects/index.html. ^,20Al-Aly Z, Bowe B, Xie Y. Long COVID after breakthrough SARS-CoV-2 infection. Nat Med 2022;28(7):1461-7. doi: 10.1038/s41591-022-01840-0.^,21Voloshyna L, Smiyan S, Voloshyn O et al. Peculiarities of clinical signs, course and treatment of musculoskeletal system lesions in post-COVID syndrome. Reumatologia 2023;61(5):339-44. doi: 10.5114/reum/172575.

In a review of five studies with more than 1600 individuals, 53% of individuals experienced Long-COVID following symptomatic COVID-19 infection, with a pooled prevalence of 22%, 21%, 14%, 12% and 11%, respectively, for fatigue, muscle or joint pain, dyspnea, neurological symptoms, and loss of taste or smell.11Ma Y, Deng J, Liu Q et al. Long-Term Consequences of Asymptomatic SARS-CoV-2 Infection: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health 2023;20(2):1613. doi: 10.3390/ijerph20021613. (Figure 3) In another study, frequently reported symptoms persisting for a year included fatigue (34.3%), irritability (18%), anxiety (15.9%), muscle or joint pain in the lower limbs (15.6%), and back pain (14.9%).9Fischer A, Zhang L, Elbéji A et al. Long COVID Symptomatology After 12 Months and Its Impact on Quality of Life According to Initial Coronavirus Disease 2019 Disease Severity. Open Forum Infect Dis 2022;9(8):ofac397. doi:10.1093/ofid/ofac397. Additionally, in an outcomes-based study, compared to individuals with prior asymptomatic SARS-CoV-2 infection the risk of breathlessness, palpitations, chest pain and confusion was found to be 243%, 152% and 192% greater, respectively, for individuals with prior symptomatic infection.2Hastie CE, Lowe DJ, McAuley A et al. Outcomes among confirmed cases and a matched comparison group in the Long-COVID in Scotland study. Nat Commun 2022;13(1):5663. doi: 10.1038/s41467-022-33415-5. In addition, 24 persistent symptoms were found. Furthermore, in some individuals, multi-organ (multi-system) effects and autoimmune diseases may occur, even years after initial infection.6Centers for Disease Control and Prevention. COVID-19. Long COVID or Post-COVID Conditions. https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects/index.html. Long-COVID significantly affects quality of life, with 35% of almost 5,000 participants with prior COVID-19 having problems with mobility, 8% with personal care, and with 42% and 38%, respectively, experiencing pain/discomfort and anxiety/depression.22Malik P, Patel K, Pinto C et al. Post-acute COVID-19 syndrome (PCS) and health-related quality of life (HRQoL)-A systematic review and meta-analysis. J Med Virol 2022;94(1):253-62. doi: 10.1002/jmv.27309.

Symptoms in Children
For children with mild/asymptomatic prior infection, the most frequently reported symptoms in one review were abnormal fatigue, neurological and respiratory disorders, respectively, in 7%, 6.8% and 6% of individuals.15Parums DV. Editorial: Long-Term Effects of Symptomatic and Asymptomatic SARS-CoV-2 Infection in Children and the Changing Pathogenesis of Common Childhood Viruses Driven by the COVID-19 Pandemic. Med Sci Monit 2022;28:e937927. doi: 10.12659/MSM.937927. In contrast, among children previously hospitalized with COVID-19, psychological, cardiac and respiratory symptoms were most common and experienced by 36.7%, 23.3% and 18.3% of these individuals, respectively. (Figure 4) Children up to 5 years-of-age were more likely to develop respiratory symptoms while adolescents were at greater risk for developing neurological and psychological symptoms. No differences were observed for males and females.

Asymptomatic/mild

Hospitalized

Oral Symptoms and Conditions

As with initial infections,3Agyeman AA, Chin KL, Landersdorfer CB et al. Smell and Taste Dysfunction in Patients With COVID-19: A Systematic Review and Meta-analysis. Mayo Clin Proc 2020;95(8):1621-31. doi:10.1016/j.mayocp.2020.05.030.^,23Amorim Dos Santos J, Normando AGC, Carvalho da Silva RL et al. Oral manifestations in patients with COVID-19: a living systematic review. J Dent Res 2021;100:141-54. https://doi.org/10.1177/0022034520957289. a significant number of patients with Long-COVID experience altered/absent sensations of taste. In a systematic review and meta-analysis, a pooled prevalence of approximately 17%, 15%, and 14% was found for at least one symptom, loss of taste and loss of smell, respectively, in patients who had experienced asymptomatic initial infections.11Ma Y, Deng J, Liu Q et al. Long-Term Consequences of Asymptomatic SARS-CoV-2 Infection: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health 2023;20(2):1613. doi: 10.3390/ijerph20021613. The calculated risk reductions compared to symptomatic individuals were 80%, 90% and 90%, respectively. In a recent survey, 29% and 37% of individuals with Long-COVID of 2 years’ duration reported impaired taste and smell sensation, respectively.16Jaramillo M, Thyvalikakath TP, Eckert G, Srinivasan M. Characteristics of Chemosensory Perception in Long COVID and COVID Reinfection. J Clin Med 2023;12(10):3598. doi: 10.3390/jcm12103598. Lastly, in a prospective observational study, 92.1% of individuals who had experienced altered taste and smell during initial infection reported that these symptoms resolved over a period of three years.24Boscolo-Rizzo P, Spinato G, Hopkins C et al. Evaluating long-term smell or taste dysfunction in mildly symptomatic COVID-19 patients: a 3-year follow-up study. Eur Arch Otorhinolaryngol 2023;280(12):5625-30. doi: 10.1007/s00405-023-08227-y.

Other Oral Manifestations
Salivary gland ectasia (causing salivary gland destruction) is found in patients with Long-COVID, associated with the hyperinflammatory response to SARS-CoV-2 and antibiotic use during acute infection.25Raediopedia. Sialectasis. https://radiopaedia.org/articles/sialectasis.^,26Gherlone EF, Polizzi E, Tetè G et al. Frequent and Persistent Salivary Gland Ectasia and Oral Disease After COVID-19. J Dent Res 2021;100(5):464-471. doi: 10.1177/0022034521997112.^,27Alfaifi A, Sultan AS, Montelongo-Jauregui D et al. Long-Term Post-COVID-19 Associated Oral Inflammatory Sequelae. Front Cell Infect Microbiol 2022;12:831744. doi: 10.3389/fcimb.2022.831744. Among more than one hundred individuals previously hospitalized with COVID-19, at 3 to 4 months salivary gland ectasia and oral manifestations overall were present in 43% and approximately 84% of individuals, respectively.26Gherlone EF, Polizzi E, Tetè G et al. Frequent and Persistent Salivary Gland Ectasia and Oral Disease After COVID-19. J Dent Res 2021;100(5):464-471. doi: 10.1177/0022034521997112. Other complaints post-COVID included facial pain, weak masticatory muscles and TMJ abnormalities.26Gherlone EF, Polizzi E, Tetè G et al. Frequent and Persistent Salivary Gland Ectasia and Oral Disease After COVID-19. J Dent Res 2021;100(5):464-471. doi: 10.1177/0022034521997112. Furthermore, in a review of more than 1200 patients, approximately 32%, 30%, 26% and 12%, respectively, experienced discoloration of the oral mucosa, ulceration and hemorrhagic changes, lingual mycosis, aphthous-like lesions and atrophic cheilitis.28Rafałowicz B, Wagner L, Rafałowicz J. Long COVID Oral Cavity Symptoms Based on Selected Clinical Cases. Eur J Dent 2022;16(2):458-63. doi: 10.1055/s-0041-1739445. (Figure 5) The severity and extent of these conditions was associated with increasing age, comorbidities, and initial disease severity.

Given the plethora of symptoms and conditions discussed, and needed medical care, the implications for dental and home care are considerable. In addition, cognitive impairment presents challenges in the ability of individuals to provide (and dental professionals to obtain) the required informed written consent29American Dental Association. Informed consent/refusal. Available at: https://success.ada.org/en/practice-management/guidelines-for-practice-success/managing-patients/informed-consent-refusal..

Implications for Interventions, Dental Care and Home Care

Figure 6. Changes in medication use in patients with Long-COVID.

Interventions frequently include the use of medications, and sometimes several medications. Among more than 2000 participants in a recent cohort study (2023), individuals were taking more medications on a daily basis compared to prior to experiencing Long-COVID, and a larger percentage of individuals were taking multiple drugs at the 12-month follow-up (18.7% versus 12.1%).19Gallo A, Covino M, Lipari A et al. Increase in Chronic Medications and Polypharmacy-The Multifaceted Burden of COVID-19 Disease on Public Health Care. J Pers Med 2023;13(9):1321. doi: 10.3390/jpm13091321. For example, the percentage of participants taking cardiovascular drugs increased from 35.9% to 41.6%, and for anti-thrombotics (anticoagulants and anti-platelet medications) from 13.5% to 14.7%. (Figure 6)

Medication use and polypharmacy raises the issue of adverse events, drug-drug interactions, and drug-disease interactions.30Desai M, Park T. Deprescribing practices in Canada: A scoping review. Can Pharm J (Ott) 2022;155(5):249-57. doi: 10.1177/17151635221114114. Anticoagulants reduce the risk of blood clots and thrombosis, while anti-platelet medications are used for atherosclerotic cerebrovascular accidents to prevent arterial ischemic events.31Schmode A, Ackman M, Bungard TJ. Antiplatelet, anticoagulant or both? A tool for pharmacists. Can Pharm J (Ott) 2019;152(5):291-300. doi: 10.1177/1715163519866232. Consideration must be given to the patient’s specific medication and dose, and the type of dental procedure, and the potential for excess bleeding during or after the procedure. The American Dental Association provides an overview of the different categories of anti-thrombotics and general recommendations, noting consultation with the patient’s physician.32American Dental Association. Oral Anticoagulant and Antiplatelet Medications and Dental Procedures. https://www.ada.org/resources/research/science-and-research-institute/oral-health-topics/oral-anticoagulant-and-antiplatelet-medications-and-dental-procedures.

In addition, fatigue and shortness of breath may make it difficult for patients to tolerate dental treatment. In a recent cohort study, the percentage of individuals utilizing chronic oxygen supplementation had increased from 0.1% to 2.2% after contracting Long-COVID.19Gallo A, Covino M, Lipari A et al. Increase in Chronic Medications and Polypharmacy-The Multifaceted Burden of COVID-19 Disease on Public Health Care. J Pers Med 2023;13(9):1321. doi: 10.3390/jpm13091321. Given these facts, oxygen levels should be monitored, and supplemental oxygen may be required.

From an oral health perspective, dry mouth is a frequent adverse event for many medications, including among those used to treat symptoms and conditions associated with Long-COVID.14Fischer A, Badier N, Zhang L et al. Long COVID Classification: Findings from a Clustering Analysis in the Predi-COVID Cohort Study. Int J Environ Res Public Health 2022;19(23):16018. doi: 10.3390/ijerph192316018.^,33Scully C. Drug effects on salivary glands: dry mouth. Oral Dis 2003;9:165-76. Dry mouth may also be related to salivary gland infection or ectasia, systemic inflammation, a neurological pathway, a hyperinflammatory response, or cardiovascular dysfunction.26Gherlone EF, Polizzi E, Tetè G et al. Frequent and Persistent Salivary Gland Ectasia and Oral Disease After COVID-19. J Dent Res 2021;100(5):464-471. doi: 10.1177/0022034521997112.^,34Chern A, Famuyide AO, Moonis G, Lalwani AK. Sialadenitis: a possible early manifestation of COVID-19. Laryngoscope 2020;130(111):2595-97. doi:10.1002/lary.29083.^,35Wang C, Wu H, Ding X et al. Does infection of 2019 novel coronavirus cause acute and/or chronic sialadenitis? Med Hypotheses 2020;140:109789. doi:10.1016/j.mehy.2020.109789. The sequelae of dry mouth include oral discomfort and an increased risk for dental caries, dental erosion, oral infections and halitosis.31Schmode A, Ackman M, Bungard TJ. Antiplatelet, anticoagulant or both? A tool for pharmacists. Can Pharm J (Ott) 2019;152(5):291-300. doi: 10.1177/1715163519866232. In addition, adverse events associated with medication use include other oral manifestations.36Yuan A, Woo SB. Adverse Drug Events in the Oral Cavity. Oral Surg Oral Med Oral Pathol Oral Radiol 2015;119(1):35-47. For patients with oral manifestations of Long-COVID, depending on the lesions, management may include use of antimicrobial rinses, corticosteroids and/or other medications.7Malkova A, Kudryavtsev I, Starshinova A et al. Post COVID-19 Syndrome in Patients with Asymptomatic/Mild Form. Pathogens 2021;10(11):1408. doi: 10.3390/pathogens10111408. Some of the medications that increase risk for infection include corticosteroids, biologics and other immunomodulatory drugs.

Other Considerations

Over the last 3 years, new SAR-SoV-2 variants have appeared, and recent data suggests that the risk of Long-COVID is reduced following infection with the Omnicron variant compared to the earlier Delta variant.13Boufidou F, Medić S, Lampropoulou V et al. SARS-CoV-2 Reinfections and Long COVID in the Post-Omicron Phase of the Pandemic. Int J Mol Sci 2023;24(16):12962. doi: 10.3390/ijms241612962.^,37Antonelli M, Pujol JC, Spector TD et al. Risk of long COVID associated with delta versus omicron variants of SARS-CoV-2. Lancet 2022;399:2263-4. However, the type and relative occurrence of Long-COVID symptoms does not appear to have changed. The rate of infection and the percentage of reinfections with Omnicron has, on the other hand, increased.13Boufidou F, Medić S, Lampropoulou V et al. SARS-CoV-2 Reinfections and Long COVID in the Post-Omicron Phase of the Pandemic. Int J Mol Sci 2023;24(16):12962. doi: 10.3390/ijms241612962. Based on current knowledge, prior vaccination against COVID-19 may be protective and reduce risk against Long-COVID.38Ballouz T, Menges D, Kaufmann M et al. Post COVID-19 condition after Wildtype, Delta, and Omicron SARS-CoV-2 infection and prior vaccination: Pooled analysis of two population-based cohorts. PLoS One 2023;18(2):e0281429. doi: 10.1371/journal.pone.0281429.

Conclusions

Over the last 18 months, much has been learned about Long-COVID, which has been referred to as a ‘second pandemic’.19Gallo A, Covino M, Lipari A et al. Increase in Chronic Medications and Polypharmacy-The Multifaceted Burden of COVID-19 Disease on Public Health Care. J Pers Med 2023;13(9):1321. doi: 10.3390/jpm13091321. For patients with this condition, the consequences are far-reaching. Systemic and oral health may be severely impacted, and therefore quality of life, and there are substantial implications for medical and dental care of these individuals, some of which are addressed in this article. More research is needed to further understand Long-COVID, and how to reduce its prevalence and impact. This includes information on new variants as they appear, and the efficacy of vaccination as a public health measure in limiting the effects of Long-COVID on patients and society.38Ballouz T, Menges D, Kaufmann M et al. Post COVID-19 condition after Wildtype, Delta, and Omicron SARS-CoV-2 infection and prior vaccination: Pooled analysis of two population-based cohorts. PLoS One 2023;18(2):e0281429. doi: 10.1371/journal.pone.0281429.

In the meantime, a full medical history is essential (as always), including details on all medications the patient is taking. Patients should receive a full oral evaluation, be counselled on the risks to oral health and on appropriate home care, receive advice on relieving dry mouth if relevant, and be provided with appropriate interventions for the prevention and management of oral diseases and manifestations of Long-COVID. Dental professionals must be alert to potential complications, medications, and adverse events. Collaboration with medical professionals in determining appropriate care is an important component of treatment for patients with Long-COVID.

References

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• 3.Agyeman AA, Chin KL, Landersdorfer CB et al. Smell and Taste Dysfunction in Patients With COVID-19: A Systematic Review and Meta-analysis. Mayo Clin Proc 2020;95(8):1621-31. doi:10.1016/j.mayocp.2020.05.030.
• 4.Rothan HA, Byrareddy SN. The epidemiology and pathogenesis of coronavirus disease (COVID-19) outbreak. J Autoimmun 2020; doi:10.1016/j.jaut.2020.102433.
• 5.Soriano JB, Murthy S, Marshall JC et al. A clinical case definition of post-COVID-19 condition by a Delphi consensus. Lancet Infect Dis 2022;22(4):e102-7. doi: 10.1016/S1473-3099(21)00703-9.
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