Sty (Hordeolum)
A sty develops when a pimple-like abscess forms in one or more of the specialized oil glands that line the eyelid. The term sty (or stye, as it is sometimes spelled) derives from the old English word stigend, which means "to rise." Hordeolum, the medical term for a sty, is Latin for "a small grain of barley," which describes its appearance.
Most sties develop at the base of an eyelash on the outside of an eyelid, but some, called internal hordeola, form on the inner edge. Regardless of where they appear, sties are usually caused by staphylococcal bacteria, organisms that normally live on the skin and in the nasal passages without causing harm.
Sties occur equally in women and men of all ages, but for reasons that are unknown, some people, especially children, seem to be particularly vulnerable to recurrent episodes. Exposure to chemical and environmental irritants, including tobacco smoke, is thought to increase the risk of sties.
An external sty typically begins as a red, itchy or sore spot that swells and eventually forms a pink or yellow head, similar to that of a pimple or small boil. The entire eyelid and surrounding area may be red and painful. The eye may feel as if something is in it and be more sensitive to light. In most cases, the sty comes to a head and ruptures in a few days and then heals itself.
An internal sty is more painful, but is not as readily apparent as an external one. Lifting the eyelid reveals the yellowish head, which is not as likely to rupture as that of an external sty. Instead, an internal sty may gradually subside in three or four days. Recurrence is more common than with external sties.
Diagnostic Studies and Procedures
Most sties can be diagnosed on the basis of their symptoms and appearance. In unusual cases, a doctor may order a laboratory culture of discharge from the sty to identify the infecting organism and prescribe an antibiotic.
Medical Treatments
Most sties can be handled with self-treatment, but medical care is warranted if a sty fails to rupture or does not drain spontaneously after it bursts. When a sty does not burst or drain, it may be opened with a fine-tipped lance, allowing a doctor to express its contents. To hasten healing and help prevent recurrence, an antibiotic ointment or cream may be applied to the edge of the eyelid several times a day. Antibiotic eyedrops also may be prescribed, especially for internal sties, to protect the eye itself from infection. In such cases, the drops should be applied to both eyes as a precaution.
Alternative Therapies
Herbal Medicine. Herbalists recommend washing the eyes with a cool tea made from raspberry leaves to alleviate pain. Parsley compresses are said to hasten healing of external sties. To prepare a compress, pour a cup of boiling water over a handful of fresh parsley and let it steep for 10 minutes. Soak a clean cloth in the hot tea and place it on the closed eyelid for 15 minutes. Continue with this procedure twice a day until the sty heals. A topical lotion made from eyebright is thought to help alleviate the pain and inflammation of sties.
Hydrotherapy. Warm, moist compresses applied to the eye for 10 minutes three or four times a day help bring a sty to a head. They also relieve pain and inflammation.
Naturopathy. Some practitioners attribute the recurrence of sties to an inadequate intake of vitamin A or beta carotene, its precursor. Thus, increased consumption of orange, yellow, and dark-green leafy vegetables -- all good sources of beta carotene -- may be recommended to help prevent sties from forming.
Self-Treatment
See a doctor if a sty does not improve after two days of treatment with warm compresses or if several sties develop simultaneously or recur in rapid succession. Don't try to open a sty yourself. Squeezing or pressing it can spread the infection and make it worse. Always wash your hands with soap and water before and after touching a sty, and use boiled water and sterile gauze or cloth for compresses.
After a sty has come to a head and burst, you can help release the pus by gently easing the tip of the involved eyelash out of the infected area. Use a dilute solution of baby shampoo to bathe the eyelid and remove pus and any crusts that may have formed around the sty. Afterward, wash your hands again, and apply a thin layer of an antibacterial ointment.
To help prevent sties, avoid dust and other substances that can irritate the eye. If you work in an environment with irritants, be sure to wear protective goggles at all times.
If you wear removable contact lenses, be sure to clean and disinfect them daily. Never put a lens in your mouth to moisten it before putting it into your eye, as this transports germs from the mouth into the eye. Mascara and other eye cosmetics can also harbor bacteria. Replace them approximately every two or three months, and never share these items with others.
Other Causes of Eyelid Symptoms
A sty may easily be confused with a condition called chalazion, an inflammation of sebaceous glands in the eyelid. Instead of coming to a head, a chalazion forms a slowly expanding, grainy mass in the eyelid, which usually disappears on its own in a month. Sties are also similar to blepharitis, a chronic inflammation of the margins of the eyelid that can cause redness, discomfort, and sometimes ulcerations.