Apart from the complications
of bacterial and fungal infection in the sinuses, asthma is a major
problem, because of a causal or shared association between sinusitis
The relationship between
sinusitis and asthma is unclear. A number of theories have been
proposed for a causal or shared association between sinusitis and
Inflammation and overproduction
of mucus in the nasal passages and sinus cavities may eventually
affect the airways in the lung, causing them to hyperreact.
Breathing through the
mouth when the sinuses are blocked allows in large particles that
would other wise be filtered by the nasal defense system. These
particles could trigger allergic responses in the lungs that in
turn trigger asthma in susceptible people.
Cold air is a known
trigger of asthma. When nasal passages which warm air is blocked,
air is breathed through the mouth, which is colder.
Sinusitis and asthma
may share similar immune abnormalities that cause inflammation in
the airways in the lungs and sinuses.
Treatment of both allergic
rhinitis and chronic sinusitis in children who also have asthma
may reduce symptoms of asthma.
Asthmatics might not
respond to asthma treatments unless the infection is also cleared
up. It is important to treat any coexisting bacterial sinusitis
in people with asthm.