Hordeolum 2009-10-27T11:01:13Z SNOMEDCT_US:397513003 SNOMEDCT_US:1489008 An acute purulent infection of the sebaceous glands of Zeis at the base of the eyelashes, of the apocrine sweat glands of Moll or the meibomian sebacious glands often caused by staphylococcus infections. Hordeola can either occur as Hordeola externa affecting the sebaceous glands of Zeis or the apocrine sweat glands of Moll or as Hordeola interna affecting the meibomian sebacious glands. In contrast to chalazia, hordeola are extremely painful and can cause extreme local swelling. Red bump on eyelid UMLS:C4280376 Stye of eyelid HP:0010606 UMLS:C0019917 Nodular changes affecting the eyelids