Is a Sty (Stye) Contagious?

A sty, that is, a red and painful lump on the eyelid, is generally not considered contagious. The bacteria that cause a sty are not typically transmitted from person-to-person, though it may be possible in rare circumstances.

A sty (hordeolum) is a small, red, painful lump that forms at the base of an eyelash or under the eyelid. 

There are two kinds of stys:

• External hordeolum
  • Begins at the base of an eyelash
  • Mostly caused by an infection in the hair follicle
  • May look like a pimple
• Internal hordeolum
  • Forms inside the eyelid
  • Usually caused by an infection in an oil-producing gland in the eyelid

A sty is different than a chalazion, which also causes a lump on the eyelid. The differences are that a chalazion is not tender or painful, is not caused by an infection, and it often lasts longer than a sty.

Symptoms of a sty include: 

• Red and painful lump on the edge of the eyelid
  • Usually develops over a few days
  • May look like a pimple with a small pus spot at the center of the bump
• Eye tearing 
• Eyelid pain and swelling    
• Feeling as if something is in the eye
• Scratchy feeling in the eye
• Sensitivity to light
• Crustiness along the edge of the eyelid

Most styes are caused by a bacterial infection, typically Staphylococcus aureus. Staphylococcus bacteria can usually be found in the nose and does not cause any complications. But in some cases, if the bacteria are present in your nose and you rub your nose and then your eye, this can cause infection that results in a sty. 

Risk factors for developing a sty include: 

• Patients who have underlying skin conditions that affect the eyelids (e.g., acne rosacea and seborrheic dermatitis) 
• Use of eye makeup, especially eye makeup contaminated by bacteria, which can clog and inflame pores
• Blepharitis, a condition that causes swelling and redness of the eyelids at the base of the eyelashes 
• Having a sty or chalazion before
• Diabetes or other medical problems

A sty is generally not considered contagious. The bacteria that cause a sty are not typically transmitted from person-to-person. 

In rare cases, if another person comes into contact with the bacteria on an infected person and then touches their eyes, they may be able to transfer the infection, but this is rare.

A sty is usually diagnosed with a patient’s medical history and a physical exam of the lesion. No special tests are needed to diagnose a sty.

In some cases, a sty may be treated with home care to relieve symptoms and help the sty go away. Home remedies to treat a sty include: 

• Warm, wet compress: soak a clean washcloth in hot water and hold it to the eyelid for 10 to 15 minutes, 3 to 5 times daily
• Gently massage around the area with a clean finger to help the gland clear itself 

Do not:

• Squeeze or pop a sty, which can make it worse and spread the infection into the eyelid
• Wear eye makeup or contact lenses until the sty is healed

If the sty doesn’t improve within 48 hours or symptoms worsen, medical treatment for a sty includes: 

• Antibiotics
• A procedure to drain the sty