common cold and flu

common cold and flu overview and Definition

The common cold is the viral infection of the nose and throat.  It results in the inflammation of the linining  of the mucous membrane of the nasal membrane.

Flu is a respiratory distress that occurs from a viral infection.


Chronic rhinitis is described as an chronic infection which shows inflammation in the pulmonary airway and bronchial hyperresponsiveness to an allergen resulting in asthmatic condition .inflammatory cells are accumulated in respiratory bronchioles.

Physiologically, allergen inhaled results in provocation of the inflammatory system of the respiratory system resulting in increased secreation of inflammatory mediators such as methacalmine and histamine. Release of histamine from the mast cells results in activation of the prostaglandins and leukotrienes.In addition to that cytokines are also released from the mast cells which leads to Increased vascular permeability, mucus secreation and bronchospasm, and wheezing.

Triggering factors that results in  blockage of the pulmonary airway include cold air, exercise, viral upper respiratory infection, cigarette smoke, and respiratory allergens. Bronchial provocation with allergen induces a prompt early phase immunoglobulin E (IgE)-mediated decrease in bronchial airflow. Initially there is an increase in the leukocyte count in the pulmonary ares with help of CD4+ cells. The activated T-lymphocytes also direct the release of inflammatory mediators from eosinophils, mast cells, and lymphocytes. The cross-linkage of two IgE molecules by allergen causes mast cells to degranulate, releasing histamine, leukotrienes, and other mediators that perpetuate the airway inflammation. Histolopathology of the bronchial airway might shows  an inflammatory infiltrate consisting of eosinophils mast cells, lymphocytes, monocytes and neutrophils.

Clinical signs & symptoms


Throat infection

Redness or inflammation around the nose region

Nasal congestion

Post Nasal drip


Itching in eyes, nose and throat


Difficulty breathing, cough.

Swelling of your face, throat or mouth tissue.

Wheezing or difficulty swallowing.

Restlessness and anxiety.

Symptoms of flu:

  • breathing difficulties
  • pain or pressure in the chest or abdomen
  • dizziness, confusion, or loss of alertness
  • seizures
  • not urinating, which may indicate dehydration
  • severe pain, weakness, and unsteadiness
  • a fever or cough that goes away and then comes back
  • a worsening of other existing health conditions


Differential Diagnosis

Chest Xray:

The chest x ray predicts any abnormal area in the lungs

Computed tomography:

It reveals the slice of the lung. It uses both the combination of x ray and computer aided device.

It helps to analyse the size, shape and position of any lung tumour and also it helps in the detection of enlarged lymph nodes.

A nasal endoscopy: It is the instrument where a thin tube with a light source and visualizing unit at one end (endoscope) is inserted up to your nose so the physician can view the internal structure of nose clearly

A nasal inspiratory flow test:

A small device is placed over the mouth and nose to measure the air flow when you inhale the air through the nose.


It is a type of lung function test that measures how hard a person can blow air out of their lungs. It can determine the level of obstruction in the airway. The test is performed using a machine called a spirometer

Polymerase chain reaction:

This test can be used for DNA amplification and to detect the diagnosis.


The immunofluorescence test gives the antigen antibody reaction.



Stay away from contaminated areas.

Stay away from the triggering factors

If any surgical correction is indicated do it early

Follow healthy lifestyle

Use a vacuum cleaner fitted with a high efficiency particulate air such as HEPA filter- it can remove more dust than ordinary vacuum cleaners.

Wash the hands properly while coming indoors. It might reduces the infection and also the spread.

Follow healthy diet