Relentless placoid chorioretinitis: A review of four cases in pediatric and young adult patients with a discussion of therapeutic strategies.

Introduction: Relentless placoid chorioretinitis (RPC) is a rare, bilateral disease of the retinal pigment epithelium. The clinical course is prolonged and relapsing. No standard treatment has been established to date. The purpose of this case series is to report four cases of RPC in pediatric and young adult patients in which varying treatments were used, comparing them to previously published cases. Methods: A literature review was conducted to investigate currently published presentations and treatment options for RPC. A multicenter retrospective chart review was also performed on four consecutive patients. These patients were diagnosed with RPC because of new chorioretinitis lesions continuing to appear without or despite therapy for 5-36 months (2 patients), with a clinical course prolonged and relapsing, or because of the atypical location of the multiple lesions (>50) extending from the posterior pole to the equator and mid-peripheral retina (all four patients), which were not consistent with other entities like acute posterior multifocal placoid pigment epitheliopathy and serpiginous choroiditis. Results: All four cases of RPC received oral or IV steroids acutely, and three of these patients were transitioned to a steroid-sparing agent and biologic therapy: anti-TNF alpha or anti-IL-6. Quiescence of the chorioretinitis lesions was obtained after 7 months, 1 month, and 36 months; however, the latter had issues with treatment adherence. Mycophenolate mofetil was insufficient to control the disease in one patient, but tocilizumab and infliximab thereafter were effective after cessation of adalimumab due to side effects. Adalimumab when started the first month after the presentation was effective in controlling the disease in one patient. After the failure of interferon-alpha-2a, one patient displayed long-term control with infliximab. One patient did not require a steroid-sparing agent after oral prednisone taper as there was no evidence of progression or recurrence. Conclusion: This case series adds to the current knowledge regarding potential treatments for RPC, specifically the use of anti-TNF-alpha treatment and anti-IL-6 tocilizumab. In this case study, relapses of RPC were found among patients on mycophenolate mofetil and interferon-alpha-2a, and one case did not relapse on oral steroids without a steroid-sparing agent. Our findings suggest that adalimumab, infliximab, and tocilizumab may be useful medications to obtain quiescence of RPC.