Adult Onset Asthma and Periocular Xanthogranuloma (AAPOX), a Rare Entity With a Strong Link to IgG4-Related Disease: An Observational Case Report Study

Adult onset asthma and periocular xanthogranuloma (AAPOX) is a rare non-Langerhans histiocytosis characterized histopathologically by a periocular infiltration of foamy histiocytes and Touton giant cells. Benign hyperplasia with plasma cell infiltration is classically described in eyelids or lymph nodes of AAPOX patients. It is also a characteristic feature of IgG4-related disease (IgG4-RD), a new entity defined by an IgG4-bearing plasma cell infiltration of organs. To determine if AAPOX syndrome shares clinical, biological, and histopathological characteristics with IgG4-RD, we used the comprehensive clinical diagnostic criteria for IgG4-RD in a retrospective case series of three consecutive patients with histologically-proven AAPOX. Patients who were diagnosed with AAPOX at a French academic referral center for orbital inflammation between November 1996 and March 2013 were enrolled. Biopsies from ocular adnexa or other organs were systematically reexamined. For each patient, clinical and serological data, radiologic findings, and treatment were retrospectively analyzed. Two AAPOX patients fulfilled all of the diagnostic criteria for a definite IgG4-RD. One patient who lacked the serological criteria fulfilled the criteria of a probable IgG4-RD. These 3 cases of AAPOX patients fulfilled the IgG4-RD comprehensive clinical diagnostic criteria. To our knowledge, this is the first observational case report study to clearly show a strong relationship between IgG4-RD and AAPOX syndrome.