Frosted branch angiitis due to cytomegalovirus-associated unmasking immune reconstitution inflammatory syndrome: a case report and literature review

Background: Cytomegalovirus (CMV) retinitis is a common opportunistic infection in patients with acquired immunodeficiency syndrome. The common funduscopic manifestations are haemorrhagic necrotising variety and granular variety. Frosted branch angiitis (FBA), as a special form, when it occurred after antiretroviral therapy(ART), could possibly be associated with immune reconstitution. We report a case of FBA secondary to CMV infection-associated unmasking immune reconstitution inflammatory syndrome (IRIS). Case presentation: A 27-year-old man with human immunodeficiency virus infection developed FBA after 35 days of ART. The left Aqueous humour (AqH) tested positive for CMV DNA, and the patient was diagnosed with CMV retinitis. The degree of intraocular inflammation was reflected by increased levels of interleukin (IL)-6 and IL-8 in AqH. After anti-CMV treatment and continuous ART for several months, his FBA and vision significantly improved. CMV DNA became undetectable in the left AqH, and the IL-6 and IL-8 levels in AqH decreased. Conclusion: FBA could be a sign of CMV-associated unmasking IRIS. Anti-CMV treatment alone or combination with steroid treatment may be administered, depending on the changes in CMV DNA load and immunologic profile of AqH.