An Expert Panel of the Orbital Society reported criteria for the diagnosis of idiopathic orbital inflammation (IOI). The criteria were developed by a Delphi consensus approach amongst expert. Pathologic features are helpful to exclude conditions in the differential diagnosis.
Idiopathic Orbital Inflammation (IOI) may occur as a diffuse myositis (myositic) or as inflammation without diffuse myositis (nonmyositic).
Pathologic features of IOI:
(1) lymphoplasmacytic infiltrate with variable numbers of other inflammatory cells
(2) absence of granulomatous inflammation
(3) absence of vasculitis
(4) absence of necrosis
(5) IgG4-positive plasma cells <= 30 cells per high power field
(6) serum IgG4 to total IgG ratio <=40%
(7) variable fibrosis
To read more or access our algorithms and calculators, please log in or register.
