Sinusitis

Sinusitis is an inflammation of one or more of the sinuses (bony cavities) around the nose. It usually occurs as a complication of a viral upper respiratory infection or allergic inflammation in children older than 2 years of age. These conditions cause swelling of the lining of the nose and sinuses. This swelling blocks the openings that normally allow the sinuses to drain into the back of the nose, so the sinuses fill with fluid. Although nose blowing and sniffing may be natural responses to this blockage, they can make the situation worse by pushing bacteria from the back of the nose into the sinuses. Since the sinuses can't drain properly, the bacteria will multiply there, causing an infection.

Symptoms of Sinusitis: There are several signs of sinusitis that should alert you to call your pediatrician.

The persistence of symptoms of a cold or upper respiratory infection, including cough and nasal discharge lasting for more than ten days, without any improvement. The nasal discharge may be thick and yellow, or clear, or whitish, and the cough usually will continue during the day as well as at night. In some cases, a child with sinusitis will have swelling around the eyes when he wakes up in the morning. Also, a preschooler with sinusitis sometimes may have persistent bad breath along with cold symptoms. (However, this also could mean that he has put something into his nose or has a sore throat, or that he isn't brushing his teeth.)
Your child's cold is severe and accompanied by high fever and thick yellow nasal discharge. His eyes might be swollen in the early morning, and he might have a severe headache that he describes (if he's old enough) as behind or above the eyes.
In very rare cases, a sinus infection may spread to either the eye or the central nervous system (the brain). If this occurs, you'll see swelling around the eye not just in the morning but all through the day, and you should call your pediatrician immediately. If your child has a very severe headache, becomes sensitive to light, or is increasingly irritable, the infection may have spread into the central nervous system. This is serious and requires immediate medical attention.
Treatment of Sinusitis

If your pediatrician thinks your child has sinusitis, she will prescribe an antibiotic, usually for a 14- to 21-day period. Once your child is on the medication, his symptoms should start to go away very quickly. In most cases, the nasal discharge will clear and the cough will improve over a week or two. But even though he may seem better, he must continue to take the antibiotics for the prescribed length of time.

On the other hand, if there's no improvement after two to four days, your pediatrician might want to conduct some further tests, after which a different medication may be prescribed or an additional one added for a longer period of time.