Common Cold - Causes, Symptoms and Treatment

Definition:

The common cold - an acute, usually afebrile viral infection- causes inflammation of the upper respiratory tract. It accounts for more time lost from school or work than any other cause and is the most common infectious disease. Although it's benign and self-limiting, it can lead to secondary bacterial infections.

The common cold is more prevalent in children than in adults and occurs more common among the boys than in girls; and in women than in men. In temperate zones, it occurs more often in the winter months, in the tropics and during the rainy season.

Causes of Common Cold

About 90% of colds stem from a viral infection of the upper respiratory passages and consequent mucous membrane inflammation; occasionally, colds result from a mycoplasmal infection. Over a hundred viruses can cause the common cold. Major offenders include rhinoviruses, corona viruses, myxoviruses, adenoviruses, coxsackieviruses, and echoviruses.

Transmission of the virus mainly occurs through airborne respiratory droplets, contact with contaminated objects. It may also occur through hand-to-hand transmission. Children may acquire new strains from their schoolmates and pass them on to family members.

Signs and Symptoms of Common Cold

The incubation period of common cold is around 2-4 days. The common cold produces pharyngitis, nasal congestion, rhinitis, headache, and burning, watery eyes; there may he fever (in children), chills, myalgia. arthralgia, malaise, lethargy, and a hacking, nonproductive, or nocturnal cough.

As the cold progresses, clinical features develop more fully. After a day, symptoms include a feeling of fullness with a copious nasal discharge that often irritates the nose, adding to discomfort. About 3 days after onset, major signs diminish, but the "stuffed-up" feeling often persists for a week.

Reinfection (with productive cough) is common, but complications (sinusitis, otitis media, pharyngitis, lower respiratory tract infection) are rare. A cold is communicable for 2 to 3 days after the onset of symptoms.

Diagnosis of Common Cold

No explicit diagnostic test exists to isolate the specific organisms responsible for causing common cold. Consequently, the diagnosis rests on a cold's typically mild, localized, and afebrile upper respiratory symptoms. Despite infection, white blood cell count and differential are within normal limits.

A diagnosis must rule out allergic rhinitis, measles, rubella, and other disorders that produce similar symptoms. A fever higher than 100.4°F (38°C), severe malaise, anorexia, tachycardia, exudate on the tonsils or throat, petechiae, and tender lymph glands may point to more serious disorders and require additional diagnostic tests.

Treatment for Common Cold

There is no special cure for common cold. The primary treatment for common cold involves taking aspirin or acetaminophen, fluids. Aspirin eases myalgia and headache; fluids help loosen accumulated respiratory secretions and maintain hydration; and rest combats fatigue and weakness. In a child with a fever, acetaminophen is the drug of choice, as aspirin has been associated with the onset of Reyes' syndrome.

Decongestants can relieve congestion. Throat lozenges relieve soreness. Steam encourages expectoration. In infants, saline nose drops and mucus aspiration with a bulb syringe may be beneficial.

Nasal douching, sinus drainage, and antibiotics aren't necessary except in complications or chronic illness. Pure antitussives relieve severe coughs but are contraindicated with productive coughs, when cough suppression is harmful. The role of vitamin C and zinc remain controversial.

Currently, no known measure can prevent the common cold.

Special Considerations and Prevention Tips for Common Cold

• Emphasize that antibiotics don't cure the common cold and generally are not indicated unless signs and symptoms of bacterial infection are present.
  
• Tell the patient to maintain bed rest if feasible during the first few days, to use a lubricant on his nostrils to decrease irritation, to relieve throat irritation with hard candy or cough drops, to increase his fluid intake, and have him eat light meals.
  
• Inform the patient that warm baths or heating pads can reduce aches and pains but won't hasten a cure. Suggest hot or cold steam vaporizers. Commercial expectorants are available, but their effectiveness is unproven.
  
• Advise the patient against overuse of nose drops or sprays; these may cause rebound congestion.
  
• To help prevent colds, warn the patient to minimize contact with people who have colds. To avoid spreading colds, teach the patient to wash his hands often, to cover coughs and sneezes, and to avoid sharing towels and drinking glasses.