Contributor: Gordon K. Klintworth
Blepharitis is extremely common. The hordeolum is a special type of blepharitis. Several other causes of infllammation of the eyelid are uncommon (necrotizing fasciitis and juvenile xanthogranuloma). Causes of granulomatous blepharitis [blepharitis - granulomatous] include chalazion, sarcoidosis, Melkersson-Rosenthal syndrome, and infection due to Mycobacterium tuberculosis [tuberculosis], Mycobacterium leprae [leprosy] and numerous fungi [fungal infection]. The xanthogranuloma of Erdheim-Chester disease may involve the eyelid. The different types of granulomatous blepharitis need to be differentiated from the much more common chalazion. A xanthelasma may not only involve the eyelids of both eyes, but both the upper and lower eyelids. The lesion of xanthelasma is characterized by foamy macrophages with small round nuclei and abundant clear cytoplasm. Xanthoma cells result from the dissolving of lipid in the alcohol used during tissue processing. Oil red O stains fresh frozen tissue.