Table I.

Differential diagnosis between idiopathic facial aseptic granuloma (IFAG) and chalazion

	IFAG	Chalazion
Medical history	Chronic and painless facial nodule.	Small, red, tender, swollen area of the eyelid.
Clinical aspect	Single red or purplish nodule of the cheek.	Painless nodule of the eyelid
Ultrasound imaging	Well-delimited hypoechoic structure of the superficial and deep dermis with a small amount of vascularity and the lack of calcium deposits.	Cyst-like structure with a thick membrane, filled with optically clear materials.
Histology	Folliculitis and perifolliculitis with well-demarcated granulomas with palisading histiocytes, scattered foreign body giant cells, neutrophils, lymphocytes, and some plasma cells.	Granuloma with a central clear space representing lipid globules, which are composed of epithelioid cells and lipid-filled, Touton-type multinucleated giant cells intermixed with acute and chronic inflammatory cells. A pseudocapsule of connective tissue often forms around the lesion.
Treatment	None +/– topical and/or oral macrolide.	Warm compresses +/– topical antibiotics/steroids +/– surgery.
Clinical course	Spontaneous improvement in few weeks/months.	Clinical improvement in a few days.