What is a stye?

A stye (also called an external hordeoleum) is an infection of a small gland at the base of an eyelash follicle. While the red, swollen lump it causes on the eyelid can be sore and irritating, a stye normally clears up in a few days.

Causes

Eyelash follicles have a small gland at their base, called a gland of Zeis, which secretes an oily substance that coats the hair and skin.  

When bacteria get into the gland, this can lead to an infection or abscess of the gland. In most cases, bacteria called Staphylococcus aureus are responsible for causing styes.

Two cross-sections of an eyelid showing a normal eyelid and one with a stye.An infection in the glad of Zeis can result in development of a stye on the eyelid. 

Risk factors

Blepharitis is a condition in which too much oil is produced by the eyelash glands. This causes redness and inflammation and can increase the risk of developing a stye.

Conditions that are linked with blepharitis are seborrheic dermatitis and rosacea.

Other types of eyelid lumps

Not all eyelid infections are styes. Strictly speaking, the word 'stye' only refers to an infection of the gland in the eyelash follicle.

Meibomian gland abscess

Meibomian glands are another type of small gland present on the edge of the eyelid. These glands produce an oily substance that mixes with the tears, produced by the lacrimal gland, to help stop the surface of the eye from drying out.

An infection of a meibomian gland is also called an internal hordeoleum and is very similar to a stye, however, the lump will tend to point inwards, towards the underside of the lid, whereas a stye tends to be on the outer side of the lid.

Chalazion

In some cases, a meibomian gland abscess doesn't drain, despite the redness and soreness going away. This is called a chalazion and it is a solid lump in the eyelid that doesn't feel tender.

Blocked sebaceous gland

A blocked sebaceous gland on the skin of the eyelid (just like a pimple) can look like a stye.

Others

Other types of eyelid lumps can include:

  • Fluid-filled cysts;
  • Papillomas - pink, skin-colored lumps;
  • Xanthelasma - raised, yellow areas on the skin of the eyelids, and;
  • Skin cancers.

Signs and symptoms

The symptoms of a stye include:

  • A red, tender lump on the upper or lower eyelid;
  • Red, tender or sore skin surrounding the eye;
  • A gritty, uncomfortable feeling, as though there is something in the eye;
  • Watering of the eye, and;
  • Increased sensitivity to light.

A white or yellow head may appear on the lump. This is pus. Squeezing or trying to drain the pus yourself can spread the infection into the eyelid, so is not recommended.

A young boy with a stye.A stye can appear as a red and tender lump on the outer side of an eyelid. 

Pus

A bodily fluid that is the result of an inflammatory response at an infection site. Its color can range from whitish to yellow to green, depending on the composition. Pus is mainly composed of dead bacteria, white blood cells and cellular debris.

Methods for diagnosis

A simple examination by your doctor can diagnose a stye.

Types of treatment

Self care

Most styes clear up within a few days, but to help prevent the infection spreading:

  • Avoid touching the affected area;
  • Avoid squeezing or trying to drain any kind of lump on the eyelid;
  • Avoid wearing contact lenses, and;
  • Avoid wearing eye make-up.

Warm compresses

Applying heat to the eyelid by using a warm wet compress can increase blood flow to the gland, helping the body to fight the infection. Placing the compress over the eyelid for 10 minutes, four times a day, can help speed up recovery. Making the compress too hot can burn the skin.

Antibiotics

Antibiotic ointments such as, bacitracin and chloramphenicol, may be prescribed by your doctor to help clear up the infection.

Steroids

For chalazions, injections of steroids such as triamcinolone can help to shrink the lump.

Surgery

Your doctor may remove the eyelash of the affected follicle to help a stye drain. Alternatively, a small surgical incision or hole may be used to drain the abscess or chalazion.

Potential complications

Potential complications of styes and meibomian gland abscesses include:

Return of the infection

Styes and meibomian gland abscesses can come back and may require further treatment.

Cellulitis

Very rarely, infection can spread into the front layer of the eyelid (called preseptal cellulitis) and sometimes into the tissues around the eye (called orbital cellulitis), causing swelling, pain and sometimes fever.  Although extremely rare, this can threaten eyesight and is a potentially life-threatening condition, requiring immediate medical treatment.

Abscesses

A swollen area of tissue containing a build-up of pus.

Prognosis

Most styes clear up within a few days, particularly with warm compress treatment.

Prevention

People with blepharitis and those who are prone to styes and meibomian gland infections can help to prevent them by cleaning the edge (margin) of the eyelid using eye-cleansing pads.