Causes and Risk Factors of Styes

A stye, also known as a hordeolum, is a small red bump most commonly caused by a bacterial infection in an eyelash follicle or eyelid gland. Appearing as a pus-filled lump or pimple at the base of an eyelash or under the eyelid, a stye can be painful and cause swelling and redness.

Styes are commonly associated with poor hygiene, contact lens use, blepharitis, systemic conditions like seborrheic dermatitis, and using old eye makeup.

Common Causes

Blepharitis

Blepharitis, an inflammation of the eyelids, involves the edges of the eyelid (where styes are usually located). It can also affect the inner parts of the eye. This condition causes itching, burning, and a feeling that something is in the eyes. Bacterial blepharitis can lead to complications and the formation of a stye when an abscess, a collection of pus surrounded by inflamed tissue, is formed in the sweat glands or hair follicles normally present in the front layer of the eyelid.

Seborrheic Dermatitis

Seborrheic dermatitis, which causes scaly patches and red skin, affects not only the scalp but also eyebrows, the face, and eyelids. It is also a common cause of blepharitis. Oily secretions, eyelid swelling, scaling, and flaking from this condition produce itching and burning of the eyes, and can affect both the upper and lower eyelid and cause a stye.

Rosacea

Affecting up to 60% of rosacea patients, subtype 4 (ocular) rosacea involves the eyes, potentially creating a watery or bloodshot appearance, irritation, burning or stinging, swollen eyelids, and styes. A medical study of ocular rosacea patients found that 85% had dysfunctional Meibomian glands, which line the edge of the eyelid and secrete a fatty substance to keep the eyes from drying out. Styes can result if these glands become clogged.

Diabetes

People with diabetes are more prone to a number of different types of bacterial infections, especially in cases of uncontrolled diabetes, including styes.

Lifestyle Risk Factors

Poor Hygiene

While a stye can cause eyelid redness, inflammation, and even itching, rubbing the area could introduce more bacteria, irritate the stye, or even cause the infection to spread. Touching your nose and then
touching your eye can spread germs from the mucous to the eyelid, potentially leading to a stye.

Contact Lens

Washing your hands before inserting contact lenses into your eye is very important. Putting on or taking out contacts without washing your hands first can bring bacteria into your eye and cause an infection that leads to a stye.

Using Contaminated Makeup

Since eyelashes naturally harbor bacteria, when your makeup brush touches your eyelashes or eyelids, the brush becomes contaminated with those germs. After the bacteria get on the brush, inserting the brush into the makeup leads to a buildup of bacteria in the container. With each use of the product, the chance of an eye infection developing increases. When using eye makeup, the risk of infection can be reduced if you change to a new container every three to six months.

Sharing cosmetics or brushes with others causes cross-contamination or transfer of bacteria from one person to the other. Some people moisten their cosmetics by spitting into the container. Bacteria in your mouth can grow in the cosmetics, so never use makeup that contains saliva.

The risk of a stye is also greater if the oil or sweat made in glands can’t flow out properly. This may happen if the makeup you wear isn't cleaned off completely.

A Word from Verywell

If you get a stye, it is important not to squeeze or drain the stye yourself. While some medical conditions or habits may cause you to have a stye, even if you are at higher risk, you can do your part by keeping bacteria away from your eyes through proper hand washing and keeping your hands away from your eyes. If you do get a stye, consult your eye care professional about the best ways to promote healing.