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What are the differences between a stye, a chalazion, an internal hordeolum and an external hordeolum?

Home / Orbit, Eyelids, and Lacrimal System 

Contributors: BCK Patel MD, FRCS, Jay Patel BSC, Raman Malhotra FRC

Photographer:  BCK Patel MD, FRCS

When an area of inflammation is seen along the eyelid margin or within an eyelid, the terms stye, chalazion, internal hordeolum and external hordeolum are frequently used interchangeably. This is incorrect as each term describes a specific type of lesion and appearance.

In order to understand the differences between these four conditions, it is important to understand the cross-sectional anatomy of the eyelid:


Fig 1. Meibomian glands within the tarsal plates of the eyelids


Fig. 2. Cross section of the upper eyelid showing the relationship of the Meibomian gland to the orbicularis oculi muscle and the eyelashes at the eyelid margin. The Meibomian glands open at the posterior part of the eyelid margin



Fig 3. Cross-section depiction of the eyelid margin showing the relationshop of the Meibomian gland, the eyelashes and the glands of Zeis and Moll



A. Stye

A stye is caused by an infection of the gland of Zeis which opens into the eyelash follicle. Therefore, the clinical appearance will be one of erythema around the root of an eyelash. If there is active infection, there will be a yellowish-red appearance. External hordeolum is another term for a stye.


Fig 4. A stye or external hordeolum is an infection of the gland of Zeis which opens into the eyelash follicle. There will be erythema around the eyelash follicle with local tenderness


B. Chalazion

A chalazion is caused by an obstructed Meibomian gland. The retained sebaceous secretions cause enlargement and can cause local irritation with secondary non-infective granulomatous inflammation: lipogranulomatous material is present within the gland. The appearance is one of an enlarged Meibomian gland usually without tenderness and often presents as a cosmetic concern. A chalazion is also called a tarsal cyst or Meibomian cyst.


Fig 5. A Chalazion with swelling of a Meibomian gland caused by retained lipogranulomatous material in a blocked Meibomian gland. Simple chalazia tend to be non-tender but will be firm to palpation

Secondary inflammation or infection can cause local tenderness.


Fig 6. A Chalazion with erythema caused by secondary infection of the blocked Meibomian gland. These will be tender to the touch

C. Internal hordeolum

When a blocked Meibomian gland becomes inflamed with or without infection, it can “point” posteriorly with a yellowish appearance on the tarsal conjunctiva. These are generally termed “internal hordeola”.


Fig 7. Internal hordeolum: the inflamed or infected Meibomian gland points posteriorly and a yellow surface is seen on the tarsal conjunctival surface where the lesion points.


D. Internal hordeolum with granuloma

The inflamed or infected lipogranulomatous material can cause a local granuloma, similar to a pyogenic granuloma.


Fig 8. An internal hordeolum with a secondary conjunctival granuloma


Fig 9. An inflamed or infected chalazion can point outwards. Although the term “external hordeolum” is usually reserved for infections of the glands of Zeis, this term is frequently also used for such an outward-pointing inflamed chalazion.


Fig 10. Another example of an inflamed chalazion pointing outwards where it sometimes breaks

E. Chronic chalazion

A chronically blocked Meibomian gland can result in a firm nodule in the eyelid. By using the term “chronic chalazion”, the firmness and chronicity of such lesions can be recognized.


Fig 11. Chronic Meibomian gland cyst (chalazion) without local infection or inflammation resulting in a persistent, firm nodular lesion



Fig 12. Aging of the eyelids and eyelashes: Generalized thinning of the tarsal plates with atrophy of the Meibomian glands and decrease in the density of eyelashes



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  2. WillmannD, Guier CP, Patel BCK,, Melanson SW. Stye. StatPearls, Treasure Island (FL): StatPearls Publishing. Aug 2021. PMID:29083787
  3. Patel BCK, Joos ZP. Diseases of the eyelashes. StatPearls, Treasure Island (FL): StatPearls Publishing. Aug 2021. PMID:30725785