 The diagnosis is usually made by tissue biopsy, however this cannot reliably distinguish between the granulomas of OFG and those of Crohn disease or sarcoidosis.Other causes of granulomatous inflammation are ruled out, such as sarcoidosis,
Crohn disease, allergic or foreign body reactions and mycobacterial infections.OFG could be classified as a type of cheilitis (lip inflammation), hence the alternative names for the condition using the word cheilitis, and a granulomatous condition.