Viruses have always had the potential to cause persistent, weird and transient symptoms even after the inflection point of being “on the mend”. Most of us have experienced a cough that lingered for weeks or post-viral fatigue, but following the arrival of COVID people started noting unusual post-viral phenomena like hair loss and purple toes.
Altered menstrual pattern
A recent article found that women may experience amplified premenstrual symptoms, as well as altered menstrual regularity and volume following COVID-19 infection. The researchers were able to assess only three studies with a cumulative sample size of 382 — relatively small for a review article and that preempts the researchers’ conclusion that more research is needed.
This study does not establish a direct link between COVID-19 and menstrual disruption — in particular, the size of the effect was not linked to disease severity. Menstrual patterns can be influenced and altered by the stress hormone cortisol, which itself can elevate due to anything from increased exercise to having a bad week. In most participants, the menstrual cycle returned to baseline within two months and would not be expected to have any long-term effects on fertility.
Hair loss
Telogen effluvium is a syndrome of temporary hair loss following a stressful event — after a few months of rest, the follicles recover and get back to the job of hair manufacture. A 2021 review article supports the consensus that, yes, COVID infection is stressful and successfully identifying it and its transient nature as the cause of hair loss is of significant reassurance value.
Interestingly the researchers found 1810 studies to work with, of which 88 were used for the analysis. Compared to the 444 total and three usable studies available to menstrual disruption researchers, this doesn’t help Western medicine’s reputation for neglecting research on women’s health.
COVID Toe
Chilblains are characterised by tender areas of discolouration in the digits. The second half of 2020 saw an increase in the number of people going to see their doctor with this issue — and so COVID Toe (or rather Pandemic Chilblains) was born.
While most episodes of chilblains are benign and self-limiting, the potential link to COVID-19 was concerning as it was considered further evidence of the virus’ harmful effect on small blood vessels, in particular the type that supply blood to the extremities.
A recent small but detailed study has questioned a direct causative link between COVID and chilblains, suggesting that the phenomenon may have more to do with the altered behaviour of staying home for a week.
Shingles
Shingles is a reactivation of the chickenpox virus and presents as a painful rash in the territory of skin supplied by a single nerve. It can occur at any age but is more likely to appear in someone older or immunosuppressed.
A retrospective study this year (funded by pharmaceutical manufacturer GlaxoSmithKline) found that people aged over 50 are at a 15% higher risk of a shingles episode up to six months following COVID-19 infection (this rises to a 21% increased risk if the infection caused hospitalisation).
Shingles vaccination can reduce the risk and severity of an episode but the vaccine is expensive and is currently only funded by the National Immunisation Program for people aged in their 70s. Last year GlaxoSmithKline released a new shingles vaccine for private sale in Australia to people aged over 50, hence their interest in the subject.
Does x cause y
An ocean of COVID research in the past two years enlightens us on the symptoms and consequences of COVID-19, but the hyperfixation of this research is also indicative of the challenge of researching and proving causation in a pandemic.
In the good old days, to answer the question “does x cause y”, researchers could establish causation by studying two groups of people with all other variables accounted for. However when something like COVID comes along and disrupts every single facet of everyone’s lives, creating more unknowns and variables, proving that a given symptom is solely due to the interaction of the virus and the host body is difficult.
So it may be a while yet until we see fewer research articles concluding with “more research is needed”.
