Preseptal cellulitis is an infection affecting the eyelid and the skin directly surrounding the eye. This condition is not contagious. The infection is confined to the skin and soft tissues in front of a membrane called the orbital septum, meaning it cannot spread to others through typical contact. It is primarily a localized bacterial infection.
Understanding Preseptal Cellulitis
Preseptal cellulitis, also known as periorbital cellulitis, involves an infection of the eyelid and the soft tissues located anterior to the orbital septum. This orbital septum acts as a fibrous barrier, separating superficial eyelid structures from deeper tissues within the eye socket. This anatomical distinction is important because it means the infection is typically contained and does not involve the eye itself or structures behind it.
The primary cause of preseptal cellulitis is a bacterial infection, often stemming from local sources. Bacteria can enter the periorbital area through various means, such as facial or eyelid injuries, insect bites, or animal bites. The infection can also spread from nearby conditions like a stye, a blocked tear duct, or a sinus infection. Common bacteria include Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae. While Haemophilus influenzae type b was once a common cause, its incidence has decreased significantly due to widespread vaccination.
Risk factors for a person’s preseptal cellulitis include being younger than five years old, having a compromised immune system, or not having received the Hib vaccine. Sinusitis is a frequent predisposing factor, as infection can spread from the sinuses to the surrounding tissues. Trauma to the eyelids, such as scratches or cuts, also provides an entry point for bacteria.
Identifying the Symptoms
Preseptal cellulitis typically presents with signs and symptoms affecting the area around one eye. Common indicators are swelling, redness, and warmth of the eyelid and surrounding skin. The affected area may also feel tender or painful to the touch. In some instances, eyelid swelling can be so pronounced that it becomes difficult to open the eye.
A mild fever may also be present. With preseptal cellulitis, vision remains unaffected, and eye movements are normal and pain-free. The eyeball itself does not protrude forward (proptosis), which helps distinguish this condition from more serious infections.
Diagnosis and Treatment
Diagnosing preseptal cellulitis usually involves a physical examination by a healthcare provider, who assesses symptoms and reviews medical history. The examination focuses on the extent of swelling, redness, and tenderness, while also checking for normal vision and eye movement to help differentiate it from other conditions. In some cases, if a deeper infection is suspected or clinical findings are unclear, imaging tests like a computed tomography (CT) scan of the orbits may be recommended. This imaging can help determine the infection’s spread and rule out more severe conditions such as orbital cellulitis.
Treatment for preseptal cellulitis primarily involves antibiotics. For most cases, oral antibiotics are prescribed, and the infection typically resolves within about a week with proper medication. Common oral antibiotics include amoxicillin-clavulanate, cephalexin, or clindamycin, chosen based on suspected bacteria and patient allergies. It is important to complete the entire course of antibiotics, even if symptoms improve, to ensure the infection is fully eradicated.
For more severe infections, or if a patient cannot take oral medication, hospitalization might be necessary for intravenous (IV) antibiotics. If symptoms worsen, or if new signs appear such as changes in vision, pain with eye movement, or the eye beginning to bulge, immediate medical attention is necessary. These signs could indicate the infection has spread deeper, requiring urgent re-evaluation and potentially different treatment.