Diagnosing post-covid condition presents extra challenges in rheumatic disease patients.
A 50-year-old female has a seven-year history of psoriatic arthritis and 15-year history of psoriasis.
She presented with polyarthritis with severe pain and functional impairment. Her psoriatic arthritis was initially very difficult to control, requiring methotrexate, leflunomide and prednisone before finally settling with combination methotrexate and certolizumab pegol. Her psoriasis and psoriatic arthritis have been reasonably well controlled in recent years, despite a few flares requiring short course NSAIDs or prednisone.
In December 2021 (along with many others in the Omicron wave), she had her first covid infection (positive on rapid antigen test). She had typical symptoms of fever, cough, myalgias and coryzal symptoms and started antivirals (Lagevrio) on day three of symptoms. She did not require hospitalisation. She was vaccinated with three doses of mRNA vaccine.
Her respiratory tract symptoms settled within one to two weeks, but she is troubled by pronounced joint pain and fatigue. She is concerned about a flare of psoriatic arthritis triggered by the infection.
How do I assess whether this is a flare of her psoriatic arthritis or secondary to covid?
It is useful to know the pattern of previous flares of psoriatic arthritis. Have flares been oligoarticular or polyarticular? Has psoriasis flared at the same time? Have previous flares involved increased CRP or ESR? Have previous flares responded to certain medications such as NSAIDs, prednisone or other DMARDs? What examination findings have been noted on previous flares?
Her initial presentation of psoriatic arthritis involved high CRP (50) and ESR (61) and definite joint swelling and synovitis. Previous flares have usually been oligoarticular and occasionally psoriasis flared at the same time, although her psoriasis had largely settled since starting certolizumab pegol.
On assessing her after the covid infection she had whole body pain, and there was marked joint tenderness at both the joint line and around the joint margins in most joints without definite synovitis. Muscle strength is normal.
There are a few small patches of psoriasis, but it certainly did not represent a significant flare. Fatigue was extremely prominent with her sleeping many hours per day, easy fatigability during simple activities and requiring daytime naps. There were no joint effusions to allow for an aspirate.
CK is normal. CRP is 4 (normal) and ESR is 9 (normal), although it should be noted that ESR and CRP are not always reliable markers of disease activity in psoriatic arthritis. Indeed, up to 50% of people can have normal CRP and ESR at the time of diagnosis of psoriatic arthritis.
The differential here is arthralgias related to covid infection or a psoriatic arthritis flare. The history and examination of this episode seems atypical compared to her previous flares, so I was leaning toward this being arthralgias and myalgias related to covid infection.
I gave her a two-week course of prednisone 15mg daily on the basis that previous psoriatic arthritis flares had responded to this. She had no symptom relief with this, and celecoxib 200mg daily was not effective either. I feel this presentation is related to covid infection rather than psoriatic arthritis.
Unfortunately, her symptoms do not settle and persist to a varying degree beyond one year. The symptoms are consistent with long covid.
The covid pandemic has introduced many extra challenges for rheumatologists with vaccine-induced rheumatological syndromes (inflammatory arthritis and myositis to name a couple), flares of underlying autoimmune conditions from either vaccines or infections, and the challenging post-covid syndrome (long covid).
Long covid is defined as a broad range of symptoms, both physical and mental, that develop during or after covid infection and continue for more than three months from the onset of covid. They have an impact on the patient’s life and are not explained by alternative diagnoses.
There is no widely accepted clinical diagnostic criteria for long covid. The constellation of symptoms and persistent issues are like those that can occur with recovery from other infectious illnesses and critical illnesses, and are somewhat similar to the symptoms seen with fibromyalgia.
As in this case, I have found the arthralgias and myalgias in long covid typically respond quite poorly to NSAIDs and prednisone. Fatigue and problems with concentration and memory (“brain fog”) are also common manifestations of long covid and are similarly challenging to manage.
Long covid is a diagnosis of exclusion. After careful history and examination to assess for other causes (especially muscle deconditioning and atrophy), it is prudent to do a basic blood work up to exclude biochemical or endocrine causes. Check for polypharmacy and for psychotropic medications that may be contributing to fatigue. Assessment for concomitant mood disturbance is important.
Long covid is a challenging condition to treat.
I tend to treat along the lines of how I manage fibromyalgia. I encourage a gentle graded exercise program, improvement of sleep hygiene, pacing of activities and recognition of triggers of pain and fatigue.
A graded exercise program is best done in a supervised setting. It may improve endurance and reduce fatigue and dyspnoea. This approach can also give patients confidence and reassurance that they can safely resume activity.
Fatigue may be helped with the “four-P” approach to energy conservation – Planning, Pacing, Prioritisation and Positioning. There is no evidence for pharmacological agents in the treatment of fatigue. I may trial low-dose amitriptyline if there is persistent sleep disturbance, but this is not indicated if there is excessive sleep.
It is safe to recommend repeat booster vaccinations. Symptoms do not generally appear to worsen after vaccination in individuals with persistent covid symptoms, and improvement of symptoms is occasionally noted.
Hopefully there will be more research understanding the pathophysiology of fatigue and musculoskeletal symptoms of long covid. This may also improve our understanding and treatment options for other fibromyalgia-like syndromes.
Dr Andrew Jordan is a rheumatologist based in Parramatta, Sydney, with a special interest in inflammatory arthritis, gout and PRP injections.