Periorbital Cellulitis

What Is Periorbital Cellulitis?

Periorbital cellulitis is an eye infection that affects the eyelid or surrounding areas. It's also referred to as preseptal cellulitis.

It's mainly characterized by swelling of the eyelid.

Periorbital cellulitis is commonly caused by resident bacteria (normal skin bacteria) or other infectious microorganisms.

It primarily manifests after an eye injury, such as a scratch or insect bite that leaves your eye tissues vulnerable. Or, it can develop if the bacteria inside a stye spreads.

However, some underlying conditions such as sinusitis increase the risk of periorbital cellulitis.

This infection is similar to a rare but more severe condition called orbital cellulitis. This one affects the eyeball and the surrounding tissues.¹

According to recent studies, periorbital and orbital cellulitis can occur at any age. However, it is more common among children (pediatric periorbital cellulitis).²

Unlike orbital infections, periorbital cellulitis does not affect the eyeball. However, if left untreated, it may advance to orbital cellulitis.

Symptoms of Periorbital Cellulitis

Periorbital cellulitis typically affects one side of the face.

Common symptoms include:

• Eyelid swelling 
• Red-eye
• Eye pain
• Tenderness to touch
• Difficulty opening the affected eye
• Discoloration of the eyelid
• Fever (less common)
• Teary eyes
• Eye discharge (less common)
• Decreased vision (less common)

According to the British Association of Dermatologists, white skin may appear pink or red when infected.³ On the other hand, black and brown skin may appear purple. 

Causes of Periorbital Cellulitis

For the infection to develop, infectious agents have to come into contact with the eye tissues. These include:

• Bacteria
• Viruses
• Parasitic worms
• Fungi (rare cases)

However, the majority of periorbital cellulitis cases are due to bacterial infections.

A bacterial infection may spread from a sinus infection (sinusitis) or another area of the eye.

It may also happen due to minor trauma to the eyelids, such as a bug bite or an accidental scratch. In this case, bacteria gain access to the wound, causing an infection.

Common bacteria that cause this condition include:

• Staphylococcus species such as the methicillin-resistant Staphylococcus aureus (MRSA)⁴
• Streptococcus species such as Streptococcus pneumoniae and Streptococcus pyogenes
• Haemophilus influenzae

Less common causative bacteria include:

• Acinetobacter 
• Bacillus
• Mycobacterium
• Pseudomonas
• Neisseria
• Nocardia
• Proteus
• Pasteurella

In rare cases, fungi such as Mucorales and Aspergillus can cause periorbital cellulitis.⁵

Risk Factors for Periorbital Cellulitis

The predisposing factors for periorbital cellulitis include:⁶

• Insect bites. A common risk factor in children
• Trauma to the face or eyelids. A common risk factor in adults
• Dental abscess. This is a common risk in children
• Upper respiratory infection. A common risk factor in both adults and children
• Sinusitis. This is a common risk factor in adults.

A 2018 study found that periorbital cellulitis's most common risk factors are upper respiratory infection and sinusitis. The most common causal agents are Streptococcus species.⁷

Signs You Need to See an Eye Doctor

Periorbital cellulitis can be a dangerous infection. It can spread to other areas and cause complications. With proper treatment, you can stop the spread of the infection.

Below are signs that you need to contact a doctor:

• If your eye swells or becomes red
• If you notice an injury or tenderness of the skin around the eye 
• If a fever develops
• If your eye looks like it's bulging outwards (proptosis)

This condition may not be accompanied by pain or fever. However, if you or a loved one is experiencing fever and swelling, and it's difficult to open or move the affected eye, reach out to your healthcare professional for professional advice.

Complications

If left untreated, periorbital cellulitis may lead to the following serious complications:

• Orbital cellulitis. It's more severe and accompanied by bulging of the eye (proptosis) eyes and vision impairment
• Orbital abscess. This is the development of pus within the orbital tissue
• Cavernous sinus thrombosis. This is a blood clot that forms in the sinuses and ends up affecting the second eye.⁸ It can progress to intracranial infection.
• Vision problems or blindness. As the infection spreads, it impairs essential parts that enable your eyes to see.

How Periorbital Cellulitis is Diagnosed

If your doctor suspects periorbital cellulitis, they'll begin by a physical examination of your eyes for signs of injury.⁹

In addition, your doctor may examine your eye movements and response to light.

They may use tools such as X-rays and CT scans to have a clear picture of the infected area.

If your doctor suspects that underlying problems are the cause of the infection, they will do further investigation.

In this case, they may take a fluid sample such as blood cultures from the affected eye or other areas to find out the type of bacteria causing the problem.

For example, if sinusitis is the suspected cause, your doctor will take a sample of the paranasal sinus fluid to investigate further.

The paranasal sinus is the drainage that keeps the nose free of harmful bacteria. It is located in your head near the nose and eyes.

Once your doctor identifies the bacteria causing your eye infection, they will then proceed to administer treatment.

Treatment Options for Periorbital Cellulitis

The treatment choices will be determined by the person's age and the stage of the infection.¹⁰

Previously, periorbital cellulitis was treated using amoxicillin-clavulanic acid, cefpodoxime, or cefdinir. 

However, the rise of methicillin-resistant Staphylococcus aureus (MRSA) has changed how this infection is treated.

The currently recommended treatment options are:

• Clindamycin
• Trimethoprim-sulfamethoxazole (TMP-SMX)
• Doxycycline

Doctors will give oral antibiotics for infections in patients above the age of one year.

However, hospitalization will be required for infants under the age of one year and those suffering from a severe infection. Those who are hospitalized are given intravenous (IV) antibiotics.

The antibiotics should start working within 24 to 48 hours. However, you may need a follow-up visit to ensure the infection is completely gone.

Prognosis (Outlook)

Treatment is almost always effective in getting rid of periorbital cellulitis. Although it may affect anyone, the infection is more frequent in children.

If periorbital cellulitis is left untreated, the infection extends into the eye socket, surrounding tissues, and the eyeball itself, resulting in orbital cellulitis.

Orbital cellulitis is much severe and may result in vision loss.

It may also lead to life-threatening conditions, including sepsis (extreme response to an infection) and meningitis.