A stye, medically known as a hordeolum, is a common condition presenting as a red, tender bump on the eyelid margin, similar to a small pimple or boil. It is an acute, localized infection of the eyelid’s oil glands or hair follicles. While the stye itself is a contained infection, the bacteria that cause it can certainly be transferred from the affected eye to others. Though not contagious like a common cold, the potential for transmission of the bacteria exists through specific kinds of contact.
The Bacterial Origin of Styes
A stye is fundamentally a bacterial infection that has localized within the structures of the eyelid. The primary causative agent in approximately 90% of cases is Staphylococcus aureus, a bacterium commonly found on human skin and in the nose. This bacterium is generally harmless, but it becomes opportunistic when conditions allow it to proliferate, such as when an oil gland becomes blocked.
The infection targets specific small glands near the eyelashes, leading to the characteristic painful swelling. An external stye, the most common type, is an infection of the sebaceous glands of Zeis or the glands of Moll. When they become obstructed, the trapped secretions provide a perfect environment for the Staphylococcus bacteria to multiply.
The bacteria thrive in the stagnant, blocked glands, leading to an inflammatory response that results in the pus-filled abscess. The pus and discharge from the stye are highly concentrated sources of the contagious bacteria.
Transmission Pathways of the Bacteria
The mechanism of spread relies entirely on the physical transfer of the bacteria from the infected area to a vulnerable site on another person or the same person’s other eye. Transmission usually occurs through indirect contact via contaminated objects or hands. For instance, a person with a stye may unconsciously touch or rub their eye, transferring the bacteria onto their fingers.
These contaminated hands can then touch surfaces like doorknobs, elevator buttons, or shared electronics, creating a pathway for others to pick up the bacteria. If another person touches that contaminated surface and subsequently rubs their own eye, the bacteria are introduced to a new host, potentially leading to a new stye. This is why styes are considered rarely contagious, as a direct chain of unhygienic events must occur for the infection to spread.
Sharing personal items significantly increases the risk of bacterial transfer. Using the same towel or washcloth as someone with a stye can directly introduce the bacteria to the eyelid margin. Eye makeup, particularly mascara or eyeliner, can harbor bacteria, and sharing these items is a common transmission route. An individual can reinfect themselves or spread the stye to their other eye by touching the infected eyelid and then touching the uninfected one without washing their hands.
Essential Hygiene for Preventing Spread
Preventing the spread of stye-causing bacteria centers on personal hygiene. The most effective action is frequent and thorough handwashing with soap and water for a minimum of 20 seconds, especially before touching the face or eyes.
It is important to avoid touching or rubbing the affected eye entirely, as this is the primary way the bacteria is transferred to hands and surfaces. Individuals should never attempt to squeeze or “pop” a stye, as this action releases the pus, which is rich in bacteria, and significantly increases the risk of spreading the infection.
To prevent transmission:
- Do not share personal items that come into contact with the face or eyes, such as towels, pillowcases, or washcloths.
- If a person uses eye makeup during the infection, discard all products used, including applicators, to prevent future re-infection.
- Contact lens wearers should cease using their lenses until the stye is fully healed.
- Use new, clean lenses afterward to avoid contamination.