The sinuses are cavities or air-filled pockets near the nasal passage. Like the nasal passage, the sinuses are lined with mucous membranes. There are four different types of sinuses:
- ethmoid sinus: located inside the face, around the area of the bridge of the nose. This sinus is present at birth and continues to grow.
- maxillary sinus: located inside the face, around the area of the cheeks. This sinus is also present at birth and continues to grow.
- frontal sinus: located inside the face, in the area of the forehead. This sinus does not develop until a child is around 7 years old.
- sphenoid sinus: located deep in the face, behind the nose. This sinus does not develop until adolescence.
What is sinusitis?
Sinusitis is an infection of the sinuses near the nose. These infections usually occur after either a cold or an allergic inflammation. There are three types of sinusitis:
- acute sinusitis: occurs quickly and improves with the appropriate treatment
- subacute sinusitis: does not improve with treatment initially, and lasts less than three months
- chronic sinusitis: occurs with repeated acute infections or with previous infections that were inadequately treated, and lasts longer than three months