More than 200 viruses can cause the common cold – this means that each one is new to your immune system and developing a cold just after having gotten over one, or even right on top of one, is not uncommon. Colds are transmitted by personal contact, and by droplets of virus-infected fluid passing from one person to another during coughing or sneezing. Virus particles can live for several hours on doorknobs and other surfaces and then be passed on to someone else. The risk of respiratory infections is increased by exposure to cigarette smoke, which can injure airways and damage the cilia (tiny hair-like structures that help keep the airways clear). Common cold causing viruses survive better when humidity is low i.e. in the colder months of the year. Cold weather also makes the lining of the nasal passages drier and more vulnerable to viral infection.
On average, most adults develop two to three colds a year, while young children may have five to seven. Symptoms include sneezing, stuffiness in the nose, throat irritation, fever, headache, muscle aches and coughing. In children, fever could be high for one or two days, it should then reduce and be normal by day 5. Nasal discharge is usually clear the first one to three days; it then thickens and becomes yellow to greenish. A runny nose usually lasts two to seven days; coughing and nasal discharge can persist for more than two weeks.
Prevention and Treatment
Covering mouth and nose while coughing/sneezing and washing hands frequently reduces risk of spread. For someone with a cold, plenty of fluids and rest are still the best bits of advice. In general, home remedies and medications may relieve some of the symptoms of the cold but will not affect the duration of illness. Antibiotics are not needed for uncomplicated colds. Chicken soup does indeed help colds, but it appears to be the hot steam that offers the benefit; tea or any hot beverage may have the same effects. Gargling warm salt water, cough drops, or throat sprays may help relieve sore throat and reduce coughing. Petroleum jelly helps a raw nose. Acetaminophen/paracetamol help to relieve headache or fever. Several studies have linked the use of aspirin to the development of Reye’s syndrome in children with viral illnesses therefore, aspirin should be avoided but paracetamol /acetaminophen or ibuprofen (not in children below 6 months of age) would be fine for fevers.
Non- prescription cold remedies may relieve some cold symptoms but not prevent, cure, or even shorten the duration of illness. For thick phlegm, patients may try cough medications that contain guaifensin, which loosens mucus. For patients with a dry cough, a suppressant may be useful, such as one that contains dextromethorphan. Decongestants can help dry a runny nose. Nasal sprays can be recommended for not more than two to three days. Decongestants can raise blood pressure, cause anxiety and a fast heart rate and can cause difficulty in men with enlarged prostate. Pseudoephedrine and phenylephrine are popular decongestants; they work rapidly and rarely stimulate the nervous system. Infants and small children should not be given antihistamines or decongestants at all. Saline nose drops to unblock the nose, hydration and humidifying the air may be all that is needed in children with colds.
When to call the Doctor
Cold symptoms go away in 5-7 days, with the cough perhaps lingering a little longer. Need to see a doctor only if symptoms continue, coughing is bad, or in the presence of asthma, high fever, shortness of breath, or an ear infection. For persons who are susceptible to asthma, inhaled medications called bronchodilators may be effective. These drugs relax and open the airways and may relieve symptoms and reduce the duration of coughing. The most common bronchodilator used is albuterol or salbutamol. It can cause a jittery feeling and a fast heart rate. Antibiotics may be prescribed if the doctor suspects a secondary bacterial infection such as sinusitis, an ear infection or coughing due to pneumonia or bacterial bronchitis (most bronchitis is viral).