Antihistamines have no proved benefit. Ipratropium nasal spray is now available for symptomatic treatment of the cold. These viruses can change their envelope proteins as their host population develops immunity, thereby maintaining the ability to cause recurrent infection in a single host population. Influenza vaccinations for the predicted virulent strains are available in the fall months and are generally effective in preventing or decreasing the intensity and duration of infection. There is usually an abrupt onset of high fever, chills, dry cough, headache, myalgia, and prostration.
Physical exam is usually unremarkable with the exception of bibasilar rales in some patients.
Chest radiograph is usually normal. Occasionally, perihilar prominence and increased markings can be present. The development of infiltrates is suggestive of a complicating pneumonia, either viral or bacterial. The illness is usually self-limited, lasting 4 to 7 days. Rest, hydration, and acetaminophen are recommended.