Respiratory illnesses: Common cold and Flu Flashcards
What are the symptoms of a cold?
Symptoms of a cold develop over a couple of days, usually occurring in the following order:
- Sore throat which normally goes away in 2-3 days
- Nasal symptoms by the 4/5th day (sneezing, runny nose, congestion)
- Watery eyes
- Cough may develop by the 4/5th day
The following symptoms may also occur, but they’re less common in colds and more common in the flu:
- Fatigue/weakness
- Mild to moderate chest discomfort
- Muscle aches (not common)
- MILD fever (not common)*
- chills are NOT a typical sign of a cold as they’re an early sign of HIGH fever. This is common with the flu and pneumonia. So if there is HIGH fever, it’s likely not a cold.
What can cold symptoms be mistaken with and how can you tell the difference?
Cold symptoms can be mistaken with allergic rhinitis/hay fever or a sinus infection.
Cold symptoms begin more quickly and they get better in a week or two. If not, then a doctor can be seen to check if it’s an allergy.
What are the symptoms of the flu?
Symptoms of the flu occur more abruptly and are usually more severe than cold symptoms:
- Fever and/or chills (note: not everyone will have a fever with the flu)
- Cough
- Headache
- Muscle ache
- Fatigue/tiredness
- Chest discomfort
- Can also have nausea, vomiting, diarrhoea (most commonly with children)
The following symptoms can also occur, however they’re more common in colds:
- Nasal symptoms (sneezing, congestion, runny nose)
- Sore throat
What are red flags for flu symptoms that would require urgent medical attention (999/A&E)?
- Sudden chest pain/ pleuritic pain
- Difficulty breathing
- Coughing up blood (haemoptysis)
Why?
These are signs of pneumonia caused by a secondary bacterial infection.
Other secondary infections include ear infections and bronchitis.
Can colds/flu cause pneumonia?
No.
Colds and flu do not ‘turn’ into pneumonia. Instead, respiratory viral infections can predispose the patient to secondary bacterial infections which can cause viral shedding.
What does the term ‘viral shedding’ mean?
This is when a virus is released from a host cell after successfully reproducing in the host cell and exhausting its resources. The shedding happens in different stages. From the intracellular to extracellular cell, from one part of the body to another, and from inside of the body to outside of the body (at this point, it is contagious).
The virus can spread via respiratory secretions with coughing and sneezing. Viral shedding is basically a mechanism that facilitates viral transmission.
(Extra info)
This shedding is said to exist on a spectrum that can help to determine how infectious the host/patient is. e.g. a published study showed that patients infected with the new strain of coronavirus had the highest levels of viral shedding right before showing symptoms. Other
studies show that patients may continue shedding the virus after the symptoms have subsided, even those with mild symptoms (up to 8 days after symptoms are gone).
What are some other (more general) red-flag symptoms to look out for?
- Those of meningitis
- Those of sepsis
- Those of angina/heart attack
When should a patient be referred (GP/111) for flu symptoms?
- Symptoms don’t improve after 7 days** OR symptoms worsening OR symptoms persist for more than 3 weeks**
- *(remember that coughs and fatigue can persist for up to 2 weeks AFTER resolution of the fever which usually lasts for about a week)
- Child/baby with symptoms
- 65 years or over
- Pregnant
- Long-term/ Chronic condition e.g. diabetes, heart/ lung/ kidney/ neurological condition etc.
- Immunocompromised e.g. chemo, HIV.
When should a patient be referred (GP/111) for cold symptoms?
- Symptoms don’t improve after 3 weeks OR symptoms worsening
- Symptoms are suddenly worse
- High temperature or feel hot and shivery (i.e. fever and chills)
- Child/baby with symptoms
- Feel SOB or develop chest pain
- Long term/ Chronic condition e.g. diabetes, heart/ lung/ kidney/ neurological condition etc.
- Immunocompromised e.g. chemo, HIV
What are the viruses behind the common cold and the flu?
Common cold:
- Rhinovirus
- Adenovirus
- Parainfluenza
- Seasonal coronavirus (not to be confused with SARS-COV-2, the virus that caused COVID-19)
The flu:
- Influenza viruses only
Briefly summarise the difference between the cold and the flu.
They’re both respiratory infections caused by different viruses that can manifest with similar symptoms.
Cold symptoms tend to be milder and their onset is more gradual (over a few days) and doesn’t generally result in complications.
Flu symptoms come about quickly and tend to be more severe. Unlike colds which can hit any time of the year, the flu is more seasonal usually running from autumn to spring and peaking during the winter months.
Why are flu vaccines important?
The vaccine safely develops immunity to the flu. The benefits include:
- Decreasing the likelihood of getting the flu
- Reducing the severity of symptoms if you get the flu
- Reducing the chance of complications if you get the flu
- Reducing the rate of hospital admissions and mortality caused by the flu
- Protects people against the flu by limiting the overall number of exposure to the virus and cases
- Especially protects high-risk people (such as elderly, pregnant women, and chronically ill people, immunocompromised people)
- Also protects those who can’t get the vaccine
Why do flu vaccines have to be given yearly?
Because the viruses causing the flu (typically type A or influenza viruses) evolve quickly, therefore the vaccine is developed yearly to match the circulating strains.
Who shouldn’t get the flu vaccine?
- Life-threatening allergy to any of the ingredients in the vaccine e.g. severe egg allergy
- 6 months old or younger
- GBS (Guillan-Barré Syndrome)
What can be prescribed for the treatment/prophylaxis of the flu?
The following antivirals, according to NICE:
- Oral oseltamivir
or - Inhaled zanamivir
