Periorbital and orbital cellulitis are usually caused by bacterial or fungal infections of the sinuses near the nose. Insect bites or injuries that break the skin cause about 33% of ocular cellulitis cases. Ocular cellulitis may also occur in patients who have a history of dental infections.
Periorbital cellulitis: Periorbital cellulitis can be caused by local trauma (including insect bites), contagious infections (like conjunctivitis, hordeolum or lacriminal), infections caused by bacteria in the bloodstream or infections caused by sinusitis.
Orbital cellulitis: In children (especially ages six to seven), orbital cellulitis is usually the result of a bacterial sinus infection caused by Haemophilus influenzae. Other organisms such as Staphylococcus aureus, Streptococcus pneumoniae, and beta-hemolytic streptococci may also cause orbital cellulitis. Less common causes of orbital cellulitis include an infection or recent injury to the eyelid.
Periorbital cellulitis: Common symptoms include swollen, painful and red eyelids, as well as runny nose and conjunctivitis (pinkeye). Conjunctivitis is an inflammation of the mucus membrane that surrounds the eyelid and covers the sclera (white part of the eyeball). Conjunctivitis can be caused by allergies or a bacterial or viral infection. Most patients do not experience fever.
Orbital cellulitis: Orbital cellulitis may progress very quickly in children, and requires immediate medical attention to avoid loss of vision. Children are especially at risk for severe infections that could result in blindness.
Orbital cellulitis symptoms may include fever (usually 102 degrees Fahrenheit or higher), painful swelling of the upper and lower eyelids, red or purple eyelids, eye pain (especially with movement), decreased vision, proptosis (bulging or displacement of the eye), malaise (general feeling of discomfort), chemosis (swollen mucous membrane of the eyeball and eyelid) and ophthalmoplegia (paralysis of nerves that control eye movements).
Complications: Infections that spread beyond the eye socket may cause abscesses (collection of pus in cavities) in the brain or meninges (protective membranes that surrounds the brain), bacterial meningitis (infection and inflammation in the meninges), blood clots or vision loss. Complications can be prevented if antibiotics are started early to treat the infection.
Blood culture: A blood culture is used to detect the presence of organisms that cause infection. A sample of blood is taken and analyzed for harmful bacteria or fungus. The most common offenders include, H. influenzae, streptococcus, staphylococcus or diplococcus.
Computerized tomography (CT) scan: A computerized tomography (CT) scan of the eye socket should be conducted to rule out orbital cellulitis. A CT scan may also distinguish sinusitis as the cause of the infection.
Blood culture: A blood culture is commonly used to detect the presence of organisms that cause infection. A sample of blood is taken and analyzed for harmful bacteria or fungus. The most common offenders include, H. influenza, streptococcus, staphylococcus or diplococcus.
Eye exam: An ophthalmologist (eye doctor) may examine the eye to evaluate the position of the eyeball and movement of the eye. A vision test may also be performed to detect any vision loss.
Sinus x-ray: X-rays of the sinuses may show cloudiness in the sinus cavities, which is associated with orbital cellulitis.