What is Blepharitis?
Blepharitis is a very common chronic inflammatory condition characterised by intense redness, itchiness and foreign body sensation of the eyelids margins.
The condition affects people of different ages, ethnic backgrounds and genders, with no sex or age predilection [1, 2, 3, 4]. It is not usually sight-threatening but may be complicated by dry eyes due to Meibomian gland dysfunction, as well as keratopathy, corneal neovascularisation and ulceration, and permanent morphological changes of the eyelids [1].
Causes of Blepharitis
The causes of blepharitis are multifaceted and can include:
- Bacterial infection: This is the most common cause of blepharitis [5].
- Seborrhoeic dermatitis: This can cause dandruff and redness of the scalp and eyebrows, often associated with anterior blepharitis [5].
- Clogged or malfunctioning oil glands: Chronic blepharitis is a condition in which 75% of sufferers have oil glands not working adequately, hidden on the inner eyelid [5].
- Eyelash mites: They can inhibit the release of oil from glands at the root of the eyelashes, and they can make blepharitis worse [5].
- Allergies: People with seasonal allergies or other eye allergies can develop blepharitis. Allergies are the most common cause when no ulcers are found [5, 6].
- Rosacea: Wet blepharitis is always associated with rosacea, a skin condition that causes (among other things) facial flushing and blood vessels that are visible to the naked eye [5].
What is a Stye?
A stye (or hordeolum) is a small painful lump on the eyelid (the eyelid margin) caused by a bacterial infection, usually with pus inside. It can resemble a large pimple or boil.
The stye usually forms on the outside or inside of the upper or lower eyelid, although it can develop in the inner corner of both at the same time. Most of the time, only one eye is affected [7].
A stye is an infection in an oil gland or hair follicle in your eyelid. Dead skin, oil and other tiny bits of debris can become trapped within this hair follicle inside the eyelid. If bacteria manage to get in on this mixture, they can swell up into a dark red, hard, raised and sometimes painful lump [8].
Causes of Stye
A stye is an infection of either an eyelash follicle or an oil gland in the eyelid. The bacterium most often to blame is Staphylococcus, which finds its way onto the eyelid from your hands when you rub your eyes or, less commonly, from touching your contact lenses or other products that touch your eye or eyelids [7].
Many of these sometimes make stye development more likely, such as rubbing your eyes, especially if you have dirty hands and fingernails. Other behaviours, like using dirty mascara wands or eye makeup brushes, or swapping makeup, also raise the risk. Conditions that make the eyelids and eyelashes unhealthy can raise your chances of getting a stye, such as diabetes, or rosacea. [8, 9]
Similarities and Differences between Blepharitis and Stye
Blepharitis and stye are both conditions that affect the eye, but they have distinct characteristics and causes.
Differences
Blepharitis is an inflammatory disorder of the eyelid margin that is often accompanied by symptoms such as itching, sore eyelids, red or discoloured eyelids, swollen eyelids, a burning sensation (especially on the eyelid), crusts (or scabs) at the base of eyes [10, 2]. There are two types of blepharitis: anterior blepharitis, which is located where eyelashes meet with eyelids, and posterior blepharitis which is located at the inner side of the eyelid that touches the eye [10].
In contrast, a stye (or hordeolum), is an eyelid or eye lump that arises from an infection of the staphylococcus bacteria. Unless used in a collective sense, the symptom of a stye is a lump on the eyelid or around the eye. It can be tender or painful to the touch. Other symptoms are red and/or discoloured eyelids, swollen eyelids, red eyes and watering eyes [10].
Nevertheless, the two conditions diverge considerably. A stye is usually a bacterial infection, but blepharitis can result from any or all of the following: too much bacteria on your skin; dandruff from your scalp; oil accumulation in the oil glands in the eyelid; dandruff; rosacea; allergies that affect the eyelid area; and oily skin [10]. Also, blepharitis doesn’t always cause a lump, while styes are characterised by a lump on the eyelid or around the eye [10].
Similarities
From the similarities side: both of these conditions may cause red eyes and puffiness, and in both conditions, the red eye and puffiness can be caused by bacteria. Using medical terms, there can be red or discolouration of the eyelids, and the eyelids may be swollen in both red eye and red eyelid [10].