Common, Cold, inluenza, flu, coryza,

Pharmacy Clinic

Common Cold

Common cold

Other names
Cold, acute rhinitis, infections rhinitis, coryza, or catarrh

Etiology
More than 120 different viral strains that produce common cold symptoms
Rhinoviruses, adenoviruses, echoviruses, influenza viruses, parainfluenza
viruses, coxsackieviruses are isolated
Rhinovirus is the largest etiologic group.

The process of viral infection is divided into three stages:
1)        Entry into the host and nucleic acid release
2)        Genome replication and viral protein synthesis
3)        Assembly of new virus particles and their release from the cell to
infect additional host cells
When the virus invade the host cells, the inflammatory response released
causing a pathogenic symptoms

The pathologic changes are:
1)        Hyperemia: excess blood flow in the area
2)        Edema: abnormal fluid accumulation in the intercellular space
3)        Rhinorrhea: profuse watery discharge from the nasal mucus
membrane; it is the hallmark of common cold
4)        Nasal congestion: swelling of the nasal turbinates
5)        Pharyngitis in common cold: dryness or soreness rather than pain
caused by bacterial pharyngitis or tonsillitis
6)        Laryngitis: associated with hoarseness or loss of voice
7)        Feverishness: a hot or warm sensation, little or no fever is generally
present
8)        Headache occurs in early stages of the cold.
Note; influenza viruses “flu” affect the epithelial membrane and causing more
severe symptoms than common cold viruses.

Incubation period 1-4 days
Rhinorrhea starts as clear watery flow followed by thick and tenacious mucoid
and purulent secretion, largely composed of dead epithelial cells and WBCs

The combination of irritation, discharge and congestion gives rise to sneezing

The most common bacterial complications are purulent sinusitis, otitis media,
bacterial pneumonia and tonsillitis

Influenza distinguished from common cold by its epidemic occurrence and by
fever, dry cough, joint and muscle ache and more significant general malaise

Allergic rhinitis also distinguished from common cold by its persistent
symptoms of cold for weeks.

Symptoms
Runny/blocked nose
Most patients will experience a runny nose (rhinorrhoea). It is initially clear
watery fluid which is then followed by the production of thicker and more
tenacious mucus (may be purulent).
Nasal congestion occurs because of dilatation of blood vessels, leading to
swelling of the lining surfaces of the nose, the nose is further blocked by
mucus production.

Sneezing/ coughing
Occurs because the nasal passages are irritated and congested. Cough may
be present due to irritation of the pharynx.

Aches and pains/headache
Because of inflammation and congestion of nasal passages and sinuses.
Frontal headache just above the eyes may be due to sinuses. Ashes and
pains are more likely to occur with flu than the common cold.
Sinusitis may occur due to infection of the sinuses by virus or as a secondary
bacterial infection, headache accompany sinusitis especially in the frontal
area which is worsened by bending forwards or lying down

High temperature
Feeling hot, but not common, the presence of fever may indicate that the
patient having flu not cold.

Flu
Flu starts abruptly with hot and cold shivery feelings, muscular aches and
pains in the limbs, a dry sore throat, cough, and high temperature. These
symptoms usually resolve over 3-5 days. There is often a period of
generalized weakness and malaise following the worst of the symptoms.
A dry cough may present for some time. Complications appear as persistent
reproductive coughing, high persistent fever, and chest pain.

Sore throat
Some times the first sign that a cold is imminent (coming soon)

Earache
Common complication of colds, especially in children, when nasal catarrh
(nasal congestion) is present the ear can feel blocked. This is due to blockage
of the Eustachian tube which connects the air containing compartment of the
middle ear to the back of the nasal cavity. When the tube is locked the air
pressure in the ear can no longer equalized with the atmospheric pressure,
giving rise to discomfort and impaired hearing. This situation usually resolves
spontaneously, but decongestants and inhalants can be useful.
If the middle ear fills up with fluid, this becomes an ideal site for secondary
infection, and then becomes painful and otitis media takes place

Previous history
•        Chronic bronchitics need to be referred if they have a bad cold or flu-
like infection due to the possibility of secondary chest infections
•        Asthma triggered by viruses, asthmatics need to increase the dose of
bronchodilators, if no response then referral is required
•        Certain decongestants need to be avoided in case of history of high
blood pressure.

When to go to the hospital