Blepharitis is a common eye condition involving eyelid inflammation, affecting people of all ages, including children. It causes discomfort and irritation. Understanding its causes is important for effective management.
Infectious and Allergic Triggers
Bacteria are a primary cause of blepharitis in children. Staphylococcus bacteria are a frequent culprit, often residing on the skin and proliferating on the eyelid margins, leading to inflammation. This overgrowth commonly causes anterior blepharitis, affecting the eyelid’s front edge where eyelashes connect. The bacteria can cause redness, irritation, and crusting along the eyelashes.
Microscopic organisms, such as Demodex mites, can also contribute to blepharitis. These mites live in hair follicles and oil glands on the skin, including the eyelids. An overpopulation of Demodex mites can lead to irritation and inflammation, particularly in older children or adolescents. The mites can block eyelash follicles and glands, causing symptoms like itching, redness, and flaking at the base of the eyelashes.
Certain viral infections, though less common than bacterial causes, can cause blepharitis as part of a broader infection. Viruses like herpes simplex (HSV) or varicella-zoster (VZV), which causes chickenpox and shingles, can lead to eyelid inflammation. In children, herpes simplex can inflame the outer eye, including eyelids, often as blepharoconjunctivitis. Varicella zoster can also cause eyelid swelling or inflammation.
Allergic reactions are another direct trigger for blepharitis. Children can develop an inflammatory response on their eyelids when exposed to common allergens. Common allergens include pollen, dust mites, or pet dander. Certain eye drops or cosmetics can also trigger reactions, leading to swollen, itchy, and irritated eyelids.
Associated Skin and Gland Conditions
Blepharitis can also link to pre-existing medical conditions. Seborrheic dermatitis, a common skin condition characterized by oily flakes and inflammation, often seen as dandruff on the scalp or eyebrows, can extend to the eyelids. This results in oily flakes and inflammation contributing to anterior blepharitis. This condition is more common in children who also experience eczema.
Meibomian Gland Dysfunction (MGD) is another underlying factor, particularly for posterior blepharitis. Meibomian glands within the eyelids produce essential oils for the tear film, lubricating the eye. Blocked or inflamed glands affect oil production, leading to an unstable tear film and eyelid inflammation. This dysfunction creates an environment conducive to bacterial overgrowth on the eyelid margins, exacerbating blepharitis through thickened or unhealthy oil secretions.
Contributing Environmental Influences
External factors and daily habits can contribute to blepharitis development or worsening. Insufficient or improper cleaning of the eyelids is one such factor, allowing bacteria, debris, and excess oil to accumulate along the eyelid margins. This accumulation fosters inflammation. Regular eyelid hygiene is important for management.
Dry eye syndrome can make eyelids more susceptible to irritation and inflammation. A healthy tear film maintains ocular surface health and protects the eyes. When tears are insufficient or of poor quality, the eyes become dry, which can lead to or worsen blepharitis. Dryness may reduce natural resistance to bacteria, contributing to staphylococcal blepharitis.
Environmental irritants contribute to eyelid inflammation. Exposure to elements such as smoke, dust, or air pollution can directly irritate eyelid skin. These irritants can exacerbate existing inflammation or make eyelids more vulnerable to blepharitis. Certain weather conditions can also influence recurrence by affecting tear film stability and increasing eye dryness.