Hailstone (chalazion) is an inflammation of the eyelid-located meibomian gland.
This inflammation is not infectious and therefore not caused by bacteria or other agents. Usually a hailstone is formed by a blockage of the meibomian duct and manifests itself as a more or less painful inflammation on the eyelid. A hailstone can occur within a day or a few days.
The meibomian glands, which lie tube-like in the eyelids, are responsible for the sebum production, which is necessary for the structure of the tear film. Blockage of the excretory duct can lead to hailstones.
If the inflammation of the meibomian gland spreads and expands around the exit duct, even the entire lid may be swollen and reddened.
If the jammed sebum secretion does not flow from the meibomian gland into the conjunctival sac by itself, the inflammatory focus is isolated from the body's own defense cells. This results in the well palpable and not displaceable knot on the eyelid.
A hailstone ( chalazion ) either spontaneously regresses or persists, which is often an aesthetic limitation for those affected and can be surgically removed at the patient's request. It should be noted that the operation can lead to eyelid deformity or even deformation of the cornea, which can cause vision deterioration.
In contrast to the barley grain, the hailstone usually occurs in adulthood. If one repeatedly suffers from hailstones, the family doctor should clarify a possible diabetes mellitus (diabetes mellitus), which is related to the occurrence of hailstones.
Both hailstone and barley grain are benign inflammatory nodules and are not malignant neoplasms on the eyelid.