NICE Guidelines
The NICE Guideline for Long Covid (COVID-19 rapid guideline: managing the long term effects of COVID-19) was first published in December 2020 and last updated in January 2024.
This is the NICE term used to describe the signs and symptoms of COVID-19* for up to 4 weeks, regardless of the severity of infection.
This is the NICE term used to describe the signs and symptoms of COVID-19* from 4 weeks up to 12 weeks.
This comes under the Long Covid umbrella.
This is the NICE term used to describe the signs and symptoms that develop during or after an infection consistent with COVID‑19*, continue for more than 12 weeks and are not explained by an alternative diagnosis.
It usually presents with clusters of symptoms, often overlapping, which can fluctuate and change over time and can affect any system in the body.
Post‑COVID‑19 syndrome may be considered before 12 weeks, while the possibility of an alternative underlying disease is also being assessed.
This comes under the Long Covid umbrella.
* Please note that it is not uncommon for children and young people to have an asymptomatic initial infection, or for any symptoms present to be very mild. It is also possible for initial symptoms to resolve and for those, or new symptoms to then appear.
Health and Social Care Professionals
What is Long Covid?
Long Covid is the patient-coined umbrella term that reflects the range of long term effects that people may experience following an acute COVID-19 infection.
Although initially thought to be a respiratory disease, evidence shows that it is vascular, and as such, can affect any body system.
Over 200 symptoms have been identified, however, it is not the continuation of a single symptom but the combination of symptoms, level of severity and impact on everyday function that define individuals as having Long Covid.
Post-Covid Condition in Children and Adolescents
The World Health Organisation Case Definition (2023)
This definition was developed by a WHO expert panel consisting of 14 clinical researchers, five clinicians, three researchers, three patient advocates (including Sammie McFarland, LCK Founder & CEO) , one paediatric rehabilitation expert and one developmental paediatrician. https://www.longcovidkids.org/post/who-clinical-definition-for-long-covid-in-kids 'Post COVID-19 condition in children and adolescents occurs in individuals with a history of confirmed or probable SARS-CoV-2 infection, when experiencing symptoms lasting at least 2 months which initially occurred within 3 months of acute COVID-19. Current evidence suggests that symptoms more frequently reported in children and adolescents with post-COVID-19 condition compared with controls are fatigue, altered smell/anosmia and anxiety. Other symptoms have also been reported.* Symptoms generally have an impact on everyday functioning such as changes in eating habits, physical activity, behaviour, academic performance, social functions (interactions with friends, peers, family) and developmental milestones. Symptoms may be new onset following initial recovery from an acute COVID-19 episode or persist from the initial illness. They may also fluctuate or relapse over time. Workup may reveal additional diagnoses, but this does not exclude the diagnosis of post COVID-19 condition. This can be applied to children of all ages, with age-specific symptoms and impact on everyday function taken into consideration.'
The National Institute for Health Research (NIHR)
The NIHR second themed review on ‘Long Covid’ stated that there may be grounds to understand Long Covid as up to four syndromes with different underlying causes and treatment needs.
These could include:
It is important to note that these long-term effects on health may coexist in the same person.
A note on Post ICU syndrome
Post ICU syndrome is a well known phenomenon in medicine and points to. the long-term impact of the intensive care experience on a patient. Doctors and researchers must distinguish the effects of Post ICU syndrome from the damage caused directly by Covid. They both can persist even after hospital discharge.
Most children do not need ICU treatment for Covid and related conditions, but this might happen in some cases, for example, with PIMS/MIS-C.
These syndromes are consistent with the experiences shared in our support services.
Understanding the full impact of SARS-CoV-2 will take many more years but there have been many studies completed, with many more underway that have improved our understanding of aspects such as the: underlying mechanisms, symptom burden and functional impact. Treatment based studies in children and young people are lagging behind adult studies but there are a number of clinicians within the UK and globally who are treating children and young people and who share their knowledge and experiences.
Second Themed Review on Long Covid
How Can I Find Out More?
Be proactive, keep learning with us.
Join the Clinical Post Covid Society
This is a new professional society for clinicians and researchers working in post-covid condition and other post-viral conditions. It has been set up by BSPRM with support from NHS England. The aim of the society is to provide a professional network to help advance this field of medicine.
Commonly Co-occuring Conditions/Syndroms
(which may be triggered, or exacerbated by COVID-19 infection)
Paediatric Inflammatory Multisystem Syndrome (Temporarily Associated with SARS-CoV-2) also known as Multisystem Inflammatory Syndrome in Children.
Further information;
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
Up to 50% of children and young people with Long Covid also meet the criteria for a diagnosis of ME/CFS. Recognising children and young people experiencing its cardinal symptom of Post Exertional Symptom Exacerbation (PESE)/Post Exertional Malaise (PEM)/Post Exertional Neuro Exhaustion(PENE) is vital because this will impact the clinical decisions made in order to avoid harm.
Further information:
PoTS, Postural Orthostatic Tachycardia Syndrome)
IST (Inappropriate Sinus Tachycardia)
Further information;
Mast Cell Activation Syndrome and/or Histamine Intolerance.
Further information;
Research is emerging to show that a range of autoimmune conditions may be triggered or exacerbated by Covid-19
Further information;
Health & Social Care FAQs
NHS general advice on managing symptoms and seeking medical support. Long Term Effects of COVID-19 (Long Covid)
World Health Organisation (WHO) Long Covid Guidance – Information on the latest research and global understanding of Long Covid. WHO