RESUMO
Stevens-Johnson syndrome (SJS) is a debilitating condition involving the skin and mucous membranes. It is commonly the result of adverse drug reactions but can also be caused by infections. A predisposition to recurrent viral infections, such as in the case of natural killer (NK) cell dysfunction, may manifest with virally induced SJS. We present this case to suggest a possible association between NK cell dysfunction and recurrent SJS. An 11-year-old girl presents with recurring erythema, erosion, and ulceration of oral and vaginal mucosa. Small fluid-filled bumps would appear, leading to blistering and later sloughing of mucosal tissue, and bleeding would ensue. Seven separate episodes have occurred over an 8-year period, with each episode being preceded by symptoms of an upper respiratory infection. NK cell function assays were performed and NK cell phenotyping was ordered. NK cell assays showed decreased NK cell cytotoxicity at all ratios of K562 target cells. NK cell surface expression evaluation showed an immature phenotype but normal overall numbers of NK cells. NK cells are a pivotal part of the innate immune system, and, among other things, provide defense of viral infection. This case represents the manifestation of recurrent SJS as a result the lack of protection from viral illness, usually provided by NK cells in the healthy immune system.
