Blepharitis, or inflammation of your eyelid, is often caused by bacteria on your eyelid. But it’s not contagious.

Blepharitis is inflammation of your eyelid. It’s one of the most common eye conditions with studies estimating that it occurs in 37% to 50% of people at some point. It’s most common in women over 50.

People with blepharitis can develop crusty dandruff on their eyelashes and experience eyelid symptoms like:

  • redness
  • swelling
  • irritation
  • itchiness

The most common cause of blepharitis is a buildup of bacteria on the eyelid. While it’s often caused by bacteria, blepharitis is not a contagious disease and rarely causes long-term damage to the eye.

Keep reading to learn why blepharitis is not contagious.

Despite bacterial overgrowth being the main cause, blepharitis is not contagious. The bacteria that cause blepharitis are found on most people’s skin but don’t usually cause problems unless they overgrow.

Blepharitis is divided into two types:

  • Anterior blepharitis: This type affects the outer side of your eyelid and is commonly caused by bacteria or seborrheic dermatitis.
  • Posterior blepharitis: This type affects the inner part of your eyelid and is usually caused by dysfunction of the oil glands in your eyelids, which allows bacteria to grow. Skin conditions like rosacea and dandruff can also contribute.

People with blepharitis tend to have multiple types of bacteria. The most common types found in people with anterior blepharitis, in descending order, are:

  • Staphylococcus epidermidis
  • Staphylococcus aureus
  • Propionibacterium
  • Corynebacteria
  • Moraxella

Is staphylococcal blepharitis contagious?

Staphylococcal blepharitis is caused by Staphylococcus bacteria. These bacteria commonly live on your skin and in your nose without causing any problems. They’re not contagious since they’re found on most people’s skin.

Blepharitis is most common in people with certain underlying conditions. These conditions include:

  • dandruff
  • rosacea
  • oily skin
  • allergies that affect your eyelashes

It’s most common in women over 50 and can affect people of any gender or ethnicity.

Potential causes of blepharitis include:

  • Bacterial infection: A bacterial infection is the most common cause of blepharitis.
  • Seborrheic dermatitis: Seborrheic dermatitis is a condition that can cause redness and dandruff on your scalp and eyebrows. People with anterior blepharitis frequently have seborrheic dermatitis of the face and scalp.
  • Clogged or malfunctioning oil glands: About 75% of people with chronic blepharitis have malfunctioning oil glands on the inner side of their eyelids. Dysfunction of these glands can also lead to dry eyes.
  • Eyelash mites: Eyelash mites can potentially interfere with oil production from glands at the base of your eyelashes and contribute to the development of blepharitis.
  • Allergies: People with seasonal allergies or other eye allergies can potentially develop blepharitis. Allergies are the most common cause when there are no ulcers present.
  • Rosacea: Anterior blepharitis is associated with rosacea, a skin condition that causes flushing and visible blood vessels in your face. In a 2021 study, researchers found that people in South Korea with rosacea were more likely to have blepharitis, glaucoma, dry eyes, chalazia, and conjunctivitis (pink eye).

Although blepharitis is not contagious, many other types of eye infections are. Here are some that can be transmitted between people:

  • Conjunctivitis (pink eye): Conjunctivitis is the most common eye infection. Most cases are caused by viruses, and both viral and bacterial forms are highly contagious. Conjunctivitis caused by chemicals or allergies is not contagious.
  • Chlamydial conjunctivitis: Chlamydial conjunctivitis is a sexually transmitted disease caused by the same bacteria that causes chlamydia. It most often occurs in people who also have a genital chlamydia infection. The bacteria can reach your eye if you have genital fluid on your hand.
  • Keratitis: Keratitis is an infection of the clear tissue that covers your pupil and iris. Infectious keratitis can be caused by viruses, bacteria, parasites, or fungi. Non-infectious keratitis isn’t contagious.
  • Viral eye disease: Viral eye disease is usually caused by the herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2), or varicella-zoster virus (VZV). Many people are exposed to these viruses during childhood through the saliva or other bodily fluids of people who have them. You can experience eye symptoms if the virus becomes reactivated in your body.

According to the National Health Service, steps you can take to treat and prevent blepharitis include:

  • cleaning your eyelids twice a day if you currently have blepharitis and once a day when your symptoms improve
  • continuing to clean your eyes even when you don’t have symptoms
  • avoiding wearing contacts while you have symptoms
  • avoiding wearing eye makeup while you have symptoms

The following steps can help treat blepharitis:

  1. Soak two cotton eye makeup removable pads in warm water. It may be helpful to mix a small amount of baby shampoo into the water.
  2. Apply one pad to each of your closed eyes and stroke the skin of your eyelid downward for your top eyelids and upward for your bottom eyelids.
  3. Remove both pads after several minutes.
  4. Use another wet pad to wipe back and forth over your lashes to get rid of any residual debris.

General ways you can prevent eye infections include:

  • Avoid touching your eyes or face when your hands are dirty.
  • Wash your face and hands frequently with clean towels.
  • Wash your bedsheets and pillowcases weekly.
  • Avoid sharing eye or makeup products with other people.
  • Disinfect reusable lenses every day with a contact solution.

Blepharitis is the medical name for an inflamed eyelid. It’s a very common condition. It’s not contagious even though the most common cause is an overgrowth of bacteria at the base of your eyelashes.

Blepharitis can usually be treated by washing your eyelids frequently. If washing your eyes alone doesn’t improve your symptoms, your doctor may recommend other treatments like medicated eyedrops.