Stye vs Chalazion on the Eyelid: How They Differ and How to Treat Them

A Cochrane review describes a stye (hordeolum) as a common, painful inflammation of the eyelid margin, usually caused by a bacterial infection of the oil glands of the eyelid. It can be internal (involving a meibomian gland deep in the eyelid) or external, colloquially a 'stye' proper, at an eyelash. In many cases the lesion drains by itself and resolves without treatment, but the inflammation can spread to neighbouring glands or tissues, and recurrences are common. An acute internal stye that does not resolve can become chronic or turn into a chalazion.

The typical course is several days of growing pain and swelling, then a yellowish point appears, the pus drains and the complaints quickly subside. The whole thing usually lasts from a few days to two weeks. Predisposing factors are chronic inflammation of the eyelid margins, poor eyelid hygiene, unwashed hands on the eye, eye make-up kept too long and, in some people, skin diseases such as seborrhoeic dermatitis or rosacea (we write about seborrhoeic dermatitis separately).

An acute stye is an infective-inflammatory lesion, so the question of antibiotics arises, which needs a separate discussion below. It is worth noting that in the clinical literature the term 'stye' covers two entities with different locations but similar principles of management, so for the reader what matters more than the label is whether the lesion is acute and painful or chronic and hard.

A chalazion forms when the opening of a meibomian gland (the sebaceous gland in the tarsal plate of the eyelid) becomes blocked. The oily secretion accumulates, leaks into the surrounding tissue, and the body responds with a chronic inflammatory reaction. The result is a hard lump, at first sometimes slightly painful and with time usually painless. It is not a typical bacterial infection but granulomatous inflammation caused by retained oil, which is why antibiotics are not a logical first-line treatment.

The two conditions can coexist and turn into one another, and after a stye drains a hard, painless lump may remain, which is exactly a chalazion. If the lesion does not heal after a few weeks or has an unusual appearance, assessment by an eye doctor is justified, because well-designed studies describe effective methods of treating a persistent chalazion.

Warm compresses are the standard first advice in both conditions, but honesty requires saying what evidence stands behind them. The 2017 Cochrane review (Lindsley, Nichols, Dickersin) looked for randomised and quasi-randomised trials of non-surgical treatment of acute internal stye (warm compresses, lid cleaning, antibiotics, steroids) compared with observation or placebo.

This is important information: lack of evidence of effectiveness is not evidence of lack of effectiveness, and warm compresses are cheap, safe and logical (heat liquefies the retained secretion and favours drainage), so we continue to recommend them. One only needs to know that their benefit rests mainly on clinical experience. For chalazion better data are available: in the randomised study by Goawalla and Lee from 2007 a steroid injection, incision with curettage and simply advice on warm compresses were compared.

How to read this? Nearly half of chalazia (46%) resolved within 3 weeks with compresses alone, which supports the sense of a patient, conservative start. At the same time, intervention (injection or incision) removed the lesion more effectively and faster. Because the study had no control group without compresses, we do not know how many of those 46% were due to the compresses themselves and how many to the natural course.

Stye and chalazion are often treated with antibiotics, topical and oral, although the evidence base is weak. Cochrane found no randomised trials of antibiotics in acute internal stye. There is, however, a large retrospective study from a university clinic in San Francisco.

The limitations are obvious: this is an observational study in which patients treated with an antibiotic could have differed from those not treated (e.g. have more severe lesions), which usually understates the visible benefit. Even so, the result is consistent with the logic: a chalazion is not a typical infection, and a stye usually drains by itself. An antibiotic may be justified when swelling spreads beyond the eyelid (periorbital cellulitis), when there is fever or when another infection coexists, but that is a doctor's decision, not routine.

If a hard chalazion does not resolve after several weeks of compresses, enlarges, presses on the eyeball (distorting vision) or is clearly disfiguring, the eye doctor may propose a steroid injection into the lesion (usually triamcinolone) or incision and curettage under local anaesthesia. Both methods have been compared in randomised studies and in a meta-analysis.

Two seemingly contradictory results fit into a consistent picture: in the single trial both methods gave similar results (about 80%), whereas in the meta-analysis incision turned out slightly more effective after one procedure, although the difference shrinks after a second attempt. Injection is less invasive and less painful but may need repeating and may leave transient deposits; incision is more effective the first time. The choice depends on the size and location of the lesion, the patient's age and preferences, and in children and with internal lesions the eye doctor decides.

For people in whom styes or chalazia keep returning, the most important topic is usually the condition of the eyelid margins and the meibomian glands. Chronic inflammation of the eyelid margins (blepharitis) and meibomian gland dysfunction favour blocking of the gland openings and colonisation by bacteria. This is a clinical observation that is widely described, although randomised trials have not tested the whole chain: eyelid hygiene is not a proven method of preventing recurrence of stye, but a rational approach when blepharitis coexists.

With recurrent lesions doctors usually also ask about general conditions such as diabetes and sometimes suggest checking blood glucose, because disturbed sugar metabolism favours skin infections. This is a practice-based approach and not from a specific study we cite here, so treat it as a question for your doctor, not as a certainty. We write about the link between the ocular surface and dry eye in our article on dry eye syndrome.

This text does not replace an examination. Most styes and chalazia are harmless, but rare serious diseases of the eyelid can at first resemble a chalazion, which is why stubborn, atypical lesions or ones recurring in the same place must be shown to a doctor. For children, lesions on the eyelids are worth consulting an eye doctor about, who will also assess the state of the ocular surface and the vision.

A second common myth is: 'a stye is contagious like a cold'. The lesion itself does not spread so easily, but bacteria can be transferred from hands, towels and cosmetics, so hand hygiene and not sharing towels make sense. There is also no evidence that a 'bacterial stye' requires isolation.

For most people the best strategy is simple and inexpensive: warm compresses, eyelid hygiene, patience for several weeks and avoiding squeezing. An antibiotic is not the default choice. For a chalazion that persists there are proven procedures, performed as an outpatient, and at the same time it is worth addressing the causes of recurrence, above all the state of the eyelid margins. Warning symptoms of spreading swelling, fever and disturbances of vision call for a quick reaction.