Difference Between Cold and Influenza

Cold vs Influenza | Viral Respiratory Tract Infections, Common Cold, Acute Coryza | Cause, Symptoms, Clinical Practice
 

Cold and influenza both belong to viral respiratory tract infections hence both shares most of the same characteristics. Although they are considered as subsets of the same category, once the severity of the symptoms, complications and management options are taken into consideration there are differences. This article points out how common cold defers from influenza, as it is an important distinction that has to be made in day- to-day clinical practice.

Common Cold

Common cold also known as acute coryza is a viral respiratory tract infection mostly caused by rhinoviruses. The transmission of the disease is by air borne droplets, and the disease lasts for 2-3 weeks.

Disease is of rapid onset. Patients usually presents with a burning sensation at the back of the nose soon followed by nasal stuffiness, rhinorrhoea, sore throat and sneezing. Patient may run low grade fever. In pure viral infection, nasal discharge is watery but may become mucopurulent when bacterial infection supervenes.

The disease is usually self limiting and resolves spontaneously after 1-2 weeks. Bed rest is advised, and plenty of fluids are encouraged. Antihistamines, nasal decongestants, analgesics, and antibiotics are considered depending on the symptoms.

Occasionally patients may develop complications such as sinusitis, pharyngitis, tonsillitis, bronchitis, pneumonia and otitis media but comparing to influenza complication rate is very low.

Influenza

It is again a viral respiratory tract infection of sudden onset. Illness is caused by a group of myxoviruses; commonly group A and B. The disease transmission is by droplets with an incubation period of 1-4 days.

Clinically the patient presents with sudden onset of fever associated with generalized aches and pains, anorexia, nausea and vomiting. Degree of ill health may range from mild to rapidly fatal. In most of the patients, symptoms subside within 3-5 days, but may follow by ‘post influenzal asthesia’, which can persists up to several weeks.

Patients with influenza are more prone to develop complications such as bronchitis, pneumonia, sinusitis, otitis media, encephalitis, pericarditis and reye’s syndrome. Secondary bacterial invasion may occur. Toxic cardiomyopahty may cause sudden death. Demyelinating encephalopathy and peripheral neuropathy are rare complications.

In the management of such a patient, bed rest is advised till the fever settles. If the patient is developing severe pneumonia, transferring the patient to ITU is advisable, as sepsis and hypoxia may rapidly progress to circulatory collapse and death. Antiviral therapy can be considered depending on the severity. For the prevention of the disease, trivalent vaccine is given.