It’s autumn and the confusion between a cold and a Covid (Omicron infection) is very common. Sore throat, runny nose, fever, cough… How do you know what you have? When to take a test? Table of symptoms and differences with Pr Charles Cazanave, infectious disease specialist.
Stuffy, runny nose, irritated throat, slight fever, cough… Nasopharyngitis, more commonly known as a “cold”, is very common between early fall and early spring. But in the midst of a coronavirus pandemic, symptoms suggestive of a cold can be worrying and suggest a Covid infection. How to tell the difference between the two infections? What are their commonalities? How do you know what you are “incubating”? When to consult? Table of the differences between the symptoms and responses of Pr Charles Cazanave, infectious disease specialist and head of a unit in the Infectious and Tropical Diseases department at the Bordeaux University Hospital.
What do colds and Covid-19 have in common?
The coronavirus that causes nasopharyngitis does not have the same aggressiveness as the coronavirus responsible for Covid-19.
A hundred viruses can lead to a cold. These viruses are classified into two categories: rhinoviruses and coronaviruses. These are benign, unlike Sars-Cov-2, the cause of the Covid-19 pandemic. “The first symptoms of a Covid-19 infection can be very similar to those of a cold. The common cold and Covid-19 usually start with the same symptoms: we feel feverish, tired, we have a runny nose (what is called rhinorrhea or runny nose in medical terms), we have sore throat (pharyngeal pain), we sneeze and we can coughdescribes Professor Charles Cazanave. These are the symptoms of the ENT sphere which are the most frequent in both cases because SARS-CoV-2 or the virus responsible for nasopharyngitis are two viruses which pass through the nose and which descend towards the bronchi..”
Table of symptoms of a cold and Covid
| Symptoms | Common cold | Covid-19 |
|---|---|---|
| Fever | Not very high (38°C maximum) | High (39-40°C) |
| Fatigue | Moderate | Important |
| Runny nose | Important and accompanied by a stuffy nose | Possible but without nasal obstruction |
| Stuffy nose | Important | Weak |
| Sore throat | Possible (may be suggestive of angina) Be careful, an isolated sore throat is not suggestive of a cold or a Covid-19 infection. On the other hand, it can make think of angina or pharyngitis. | Possible Be careful, an isolated sore throat is not suggestive of a cold or a Covid-19 infection. On the other hand, it can make think of angina or pharyngitis. |
| Cough | Moderate | Important |
| Aches | Non-existent or weak | Significant (may be suggestive of flu) |
| Loss of sense of smell (anosmia) | None (or only due to nasal obstruction) | Possible and typical in the absence of nasal obstruction |
| Loss of taste (ageusia) | None (or only due to nasal obstruction) | Possible and typical |
| Dermatological problems | Non-existent | Possible (eruptions, purpura…) |
| Digestive signs (diarrhea) | Non-existent or rare (especially children) | Possible (classically described in young children and the elderly) |
What are the differences between the common cold and Covid?
► Different virus : the infectious agents are not the same. “The best known cold virus is the rhino virusalthough some coronaviruses (coronaviruses are a family of several viruses) can also lead to a cold. Attention, these coronaviruses are benign and have nothing to do with SARS-CoV-2, responsible for the Covid-19 epidemic“, describes the specialist. The coronavirus that causes nasopharyngitis does not have the same aggressiveness that the coronavirus responsible for Covid-19.“Everyone recovers easily from a cold, while unfortunately not everyone recovers from a Covid-19“, wishes to clarify our interlocutor.
► Different symptoms : some symptoms differ between Covid-19 and the common cold and some are only associated with one of the two diseases: “A person who has a cold has a runny nose and a stuffy nose. This can then lead to a slight loss of smell and taste, but this is simply due to nasal obstruction, while someone with Covid-19 does not have a stuffy nose, but may have a sudden loss of smell and/or taste“, explains the infectiologist. Finally, skin problems (rashes, purpura) and digestive signs (diarrhoea) can be suggestive of Covid-19 while they are almost non-existent during a cold.
► Different incubation period: the incubation of nasopharyngitis is shorter than that of Covid-19: 2-3 days for nasopharyngitis against 5-8 days for Covid-19.
► Patients of different ages: nasopharyngitis affects younger people, especially children between 6 months and 7 years, which is not the case with Covid-19. The infected people have on average 71 years oldnoted Public health France.
► Different mortality: According to Santé Publique France, Covid-19 death rate (number of deaths reported to the general population) can be estimated at 0.002%. On the other hand, one does not die of an isolated nasopharyngitis, which remains a mild infection. The immune system usually fights off the virus within a week. However, but this remains rare, in people at risk (people who have undergone a bone marrow transplant, for example), rhinoviruses can cause respiratory complications which can lead to bacterial and potentially fatal pneumonia.
Does the loss of taste and smell rather evoke the cold or the Covid?
Losing taste and smell is possible in both cases but for the common cold it is simply due to nasal obstruction. While it is a very evocative symptom of the Covid. In short, if you have a stuffy nose and a loss of smell, it’s probably a cold. On the other hand, if you lose your sense of smell and you don’t have a stuffy nose, it’s surely a Covid. In all cases, only a test can make the diagnosis.
“The only way to rule out Covid-19 is to get tested.” reminds our interlocutor. Depending on your symptoms and their intensity, you can tell the difference between a cold and Covid-19. A medical opinion is necessary so as not to miss an uncharacteristic form, especially when the symptoms persist and/or worsen.
When to get tested?
If in doubt, it is advisable to seek the advice of your doctor, initially by telephone or teleconsultation if offered. “The only way to rule out Covid-19 is to get tested“, indicates our interlocutor. From now on, the tests are paying. Continue to benefit from support, people:
- having a complete vaccination schedule (or a contraindication to vaccination);
- minors;
- identified by the “contact-tracing” carried out by Health Insurance;
- concerned by collective screening campaigns (ARS, schools, etc.);
- symptomatic on medical prescription;
- with a certificate of reinstatement less than six months old.
Thank you to Professor Charles Cazanave, infectious disease doctor and head of a unit of the infectious and tropical diseases department at the Bordeaux University Hospital.