Colds and the Flu - Diagnosis

(Page 2)

There are two forms of allergic rhinitis:

• Symptoms that appear only during allergy season are called allergic rhinitis, commonly known as hay or rose fever. [For more information see In-Depth Report #77: Allergic rhinitis.]
• Allergens in the house, such as house dust mites, molds, and pet dander, can cause year-long allergic rhinitis, referred to as perennial rhinitis.

Click the icon to see an image of common allergens.

Ruling out Sinusitis. The signs and symptoms suggestive of true acute sinusitis include the following:

• A return of congestion and discomfort after initial improvement in a cold (called double sickening)
• Purulent (pus-filled) nasal secretion
• A lack of response to decongestant or antihistamine
• Pain in the upper teeth or pain on one side of the head
• Pain above or below both eyes when leaning over

Children with sinusitis are less likely to have facial pain and headache and may only develop a high fever or prolonged upper respiratory symptoms (such as a daytime cough that does not improve for 11 - 14 days). When the diagnosis is unclear or complications are suspected, further tests may be required. [For more information see In-Depth Report #62: Sinusitis.]

Ruling Out Other Causes of Coughing

Acute Bronchitis. Acute bronchitis is usually caused by a virus and in most cases is self-limiting. The cough it causes typically lasts for about 7 - 10 days, but in about half of patients, coughing can last for up to 3 weeks, and 25% of patients continue to cough for over 1 month.

Atypical Pneumonia. Pneumonia caused by atypical organisms (for example, Mycoplasma pneumonia, Legionella) can cause symptoms similar to the flu. Only laboratory tests can diagnose the difference. [For more information see In-Depth Report #64: Pneumonia.]

Ruling out More Serious Viral Infections. Respiratory syncytial virus (RSV) and, possibly human parainfluenza viruses (HPV), are proving to be important causes of serious respiratory infections in infants, the elderly, and people with damaged immune systems. (Both also cause mild conditions.) RSV may be a much more common cause of flu-like symptoms than previously thought. In one British study of patients with flu symptoms, RSV was responsible for 22% of the cases and influenza for 32%. And among children under age 5, RSV was responsible for more flu-like cases than the flu virus itself.