Refractory periorbital edema in a 29-year-old man

A 29-year-old man developed periorbital edema which was initially diagnosed as angioedema. Further clinical investigation by orbital CT and orbital biopsy showed this to be orbital pseudotumor. Immunofluorescence staining for major basic protein clearly demonstrated tissue eosinophilia and extracellular major basic protein deposition. Orbital pseudotumor can mimic angioedema or allergic rhinoconjunctivitis and should be familiar to allergists and primary care physicians. The demonstration of striking extracellular major basic protein in biopsy specimen implicates a role for eosinophils in the pathogenesis of this disease.