Thousands of people around the world may be suffering from long Covid but are not being diagnosed or treated, say experts, because symptoms can vary so widely it’s frequently difficult to even identify the condition.
Jennifer Robertson is a classic case. After her third case of Covid-19, her heart raced all day long, and she barely slept. She had dizzy spells, pins and needles in her arm, a “buzzing feeling” in her foot, and pain in her legs and lymph nodes. She broke out in a rash. She smelled “phantom” cigarette smoke, even when none was in the air.
TIME reports that Robertson (48) had a feeling Covid-19 might have somehow been the trigger. She knew about long Covid, because her 11-year-old son has it.
“But he didn’t have anything like this,” she said. His symptoms are different, involving spiking fevers and vocal and motor tics. Her own experience was so different it was hard to believe the same condition could be to blame.
She saw a doctor in Cyprus, where her family was living then, and then in Saudi Arabia, where her husband was working. Neither visit yielded much. Then, after the family moved to Scotland last year, a specialist diagnosed long Covid.
She is still sick, and a reinfection later set her back, but she has found some relief in treatments prescribed by her doctors, including heart medication and antihistamines.
Robertson’s story highlights the many challenges of detecting, diagnosing, and treating long Covid. It produces a vast array of symptoms that can range in severity from mild to life-altering. And because it can take many forms, it can be difficult for patients and doctors to know what’s going on.
That means many people aren’t being diagnosed or treated, said Nisreen Alwan, a professor of public health at the UK’s University of Southampton who studies long Covid (and has had the condition herself).
Alwan’s research suggests there is “considerable self-doubt” among these patients, with many people questioning if they should get medical care or if they even have the condition at all.
That may be partly because media coverage tends to showcase a specific type of patient – someone who is very sick, potentially to the point of being bed-bound, and battling extreme fatigue and brain fog – so people with milder or more unusual symptoms aren’t sure whether their illness counts as long Covid, Alwan said.
It’s hard to blame people for being confused. Long Covid is so broadly defined that virtually any unexplained health issue after a case of Covid-19 that lasts at least a couple of months could fit the bill.
Additionally, some people feel better for weeks or months after their initial infection before their health deteriorates.
Range of symptoms
More than 200 symptoms have been linked to long Covid, from insomnia and hallucinations to tremors and gastrointestinal issues, and they often look very different from those of an acute Covid-19 case.
Among these post-Covid-19 conditions – or post-acute sequelae of Covid-19 (PASC) – other symptoms can also, in some cases, include immunologic phenomena that may cause allergic conditions of various kinds.
Research suggests certain symptoms are particularly tell-tale signs, including fatigue, energy crashes after physical or mental exertion, brain fog, chronic cough, and changes to smell and taste. (These symptoms are also among those the US Centres for Disease Control and Prevention says are most common.)
But there’s no universal experience of long Covid, said Dr Leora Horwitz, a professor at the NYU Grossman School of Medicine who researches the condition through the federal RECOVER Initiative.
“Undoubtedly, there are (patients) who have maybe only one of these symptoms, or maybe a totally different symptom.”
Symptom severity can vary widely, too. Some people are disabled due to long Covid, while others live fairly normal lives, at least outwardly. Some people’s symptoms also wax and wane, varying from day to day or going dormant for a while before coming back.
Research suggests about a quarter of the millions of US adults with long Covid report “significant activity limitations” that affect their ability to work, care for their families, or do other daily tasks.
But many have problems that don’t quite meet that bar, found a 2023 study that identified four levels of long Covid: “a few lingering issues”, “significant physical symptoms”, “ongoing mental and cognitive struggles”, and “numerous compounding challenges”.
In a group of about 600 long Covid patients, more than 100 fell into each category, which shows the diversity of experiences, said study co-author Keri Vartanian, who leads the Centre for Outcomes Research and Education at the multi-state Providence health system.
It’s important for both patients and clinicians to know that the condition can take so many different forms, Vartanian said, because recognition was the first step to diagnosis and treatment. Lots of people suffer from many disparate health problems, but it “might not be a multitude of symptoms”.
“It might be one or two things. It might be mental health and only mental health.”
Even if someone is properly diagnosed, of course, there’s no promise they’ll completely recover. Currently, there’s no cure for long Covid.
Even so, some post-Covid complications, like damage to a specific organ, can be effectively treated, said Dr Stanley Martin, an infectious disease doctor who treats long Covid patients at Geisinger Medical Centre in Pennsylvania.
Some symptoms that can’t be cured can also be managed to improve overall well-being, he said. (And if someone’s symptoms turn out to be related to something other than long Covid, that’s worth knowing, too.)
“This isn’t like strep throat, where I’m going to give you a week of penicillin and you’re going to be a new person,” Martin said. “This is going to happen over months and months and months, but we expect and hope to see gradual progress.”
Allergies and long Covid
An interesting large-scale analysis recently explored post-Covid long-term allergic conditions, and the ethnic variations therein.
News-Medical.Net reports that the South Korean researchers found Covid-19 upped the risk of allergies by 20%, and that risks varied from country to country.
The study team had formed a synthetic group comprising more than 22m people from South Korea, Japan and the UK, drawing participants from multinational studies to represent these ethnic backgrounds.
The South Korean segment included more than 800 000 people with an average age of 48. From the UK and Japan, the cohorts included around 325 000 and 2.5m participants, respectively.
Approximately 150 000 participants from South Korea, 77 000 from the UK, and 542 000 from Japan had been infected with SARS-CoV-2.
After adjusting for all known variables that could affect the outcome, the researchers discovered that those infected with Covid-19 showed a 20% higher occurrence of allergic diseases compared to those not infected.
This increased risk was consistent for infections from both the original and Delta variants of the virus. Specifically, the likelihood of developing asthma in those infected was more than double, at 2.25 times that in non-infected individuals.
The chance of getting allergic rhinitis was 25% higher in the infected group, though no significant increase was observed for food allergies or atopic dermatitis.
Moreover, while the risk for allergic diseases decreased over time after the infection, it didn’t disappear entirely.
This decrease in risk varied from country to country, according to the findings, published in Nature Communications.
Severity of infection, allergy risk – and vaccines
Moderate-to-severe Covid-19 was linked to a 50% higher risk of overall allergy, compared with 14% among those with mild disease.
Those who had received the vaccine had a 44% higher risk of allergy (with one dose). This was reduced by 20% after two doses of the vaccine. The two-dose cohort had comparable allergy risk as the controls, both overall and for the various allergy subgroups.
Other factors like coexisting morbidity, drinking, body mass index, exercise, and the SARS-CoV-2 strain responsible for the infection, did not show significant correlation with allergy risk.
“This is the first study that provides comprehensive evidence for the association between SARS-CoV-2 infection and subsequent incident allergic outcomes,” wrote the authors, and emphasised the relationship between Covid-19, especially moderate to severe, and subsequent allergy onset. It also indicates that vaccination with at least two doses weakens the risk of new allergies.
The findings broadly corroborate earlier research, but the researchers said there was a need for more studies on the allergic sequelae of Covid-19 on a larger and more multinational scale.
Multiple pathways have been proposed to account for the observed correlations, including T cell disruption, regulatory T cell (Treg) disturbances, and the cytokine storm in acute severe Covid-19.
Over time, the virus may be slowly cleared from the host, especially if adaptive immunity has been strengthened by vaccination against the virus.
Study 1 details
Integrating patient-reported physical, mental, and social impacts to classify long COVID experiences
Keri Vartanian, Daniel Fish, Ari Robicsek et al.
Published in Scientific Reports on 28 September 2023
Abstract
Long Covid was originally identified through patient-reported experiences of prolonged symptoms. Many studies have begun to describe long Covid; however, this work typically focuses on medical records, instead of patient experiences, and lacks a comprehensive view of physical, mental, and social impacts. As part of our larger My Covid Diary (MCD) study, we captured patient experiences using a prospective and longitudinal patient-reported outcomes survey (PROMIS-10) and free-text narrative submissions. From this study population, we selected individuals who were still engaged in the MCD study and reporting poor health (PROMIS-10 scores < 3) at 6 months (n = 634). We used their PROMIS-10 and narrative data to describe and classify their long Covid experiences. Using Latent Class Analysis of the PROMIS-10 data, we identified four classifications of long Covid experiences: a few lingering issues (n = 107), significant physical symptoms (n = 113), ongoing mental and cognitive struggles (n = 235), and numerous compounding challenges (n = 179); each classification included a mix of physical, mental, and social health struggles with varying levels of impairment. The classifications were reinforced and further explained by patient narratives. These results provide a new understanding of the varying ways that long Covid presents to help identify and care for patients.
Study 2 details
Incident allergic diseases in post-COVID-19 condition: multinational cohort studies from South Korea, Japan and the UK
Jiyeon Oh, Myeongcheol Lee, Dong Keon Yo et al.
Published in Nature Communications on 2 April 204
Abstract
As mounting evidence suggests a higher incidence of adverse consequences, such as disruption of the immune system, among patients with a history of Covid-19, we aimed to investigate post-Covid-19 conditions on a comprehensive set of allergic diseases including asthma, allergic rhinitis, atopic dermatitis, and food allergy. We used nationwide claims-based cohorts in South Korea (K-CoV-N; n = 836,164; main cohort) and Japan (JMDC; n = 2,541,021; replication cohort A) and the UK Biobank cohort (UKB; n = 325,843; replication cohort B) after 1:5 propensity score matching. Among the 836,164 individuals in the main cohort (mean age, 50.25 years [SD, 13.86]; 372,914 [44.6%] women), 147,824 were infected with SARS-CoV-2 during the follow-up period (2020−2021). The risk of developing allergic diseases, beyond the first 30 days of diagnosis of COVID-19, significantly increased (HR, 1.20; 95% CI, 1.13−1.27), notably in asthma (HR, 2.25; 95% CI, 1.80−2.83) and allergic rhinitis (HR, 1.23; 95% CI, 1.15−1.32). This risk gradually decreased over time, but it persisted throughout the follow-up period (≥6 months). In addition, the risk increased with increasing severity of Covid-19. Notably, Covid-19 vaccination of at least two doses had a protective effect against subsequent allergic diseases (HR, 0.81; 95% CI, 0.68−0.96). Similar findings were reported in the replication cohorts A and B. Although the potential for misclassification of pre-existing allergic conditions as incident diseases remains a limitation, ethnic diversity for evidence of incident allergic diseases in post-Covid-19 condition has been validated by utilising multinational and independent population-based cohorts.
TIME Magazine article – Long COVID Doesn’t Always Look Like You Think It Does (Open access)
See more from MedicalBrief archives:
Long Covid proven by biological markers – Yale study
UK scientists ID unusual new long Covid symptom
US agency launches ‘overdue’ long Covid clinical trials
Long Covid’s impact on life quality worse than some cancers – UK study