Salmonella typhi infection causing prolonged chronic illness and cutaneous leucocytoclastic vasculitis in a patient with IL 12 receptor β-1 deficiency

Abstract

Background: Interleukin-12 Receptor β1 (IL-12Rβ1) deficiency causes susceptibility to weakly virulent atypical mycobacteria and Salmonella. Genotype–phenotype correlations are weak and penetrance is not complete. Most of the culture-recovered Salmonella are with the non typhi types. Case report: We describe an 11 year old male patient with IL-12Rβ1 deficiency. He had an erythematous rash resembling Henoch Schonlein Purpura, and initially presented with slightly elevated CRP. Skin biopsy revealed leukocytoclastic vasculitis. Due to lack of evidence of an active infection, positive ANA, and positive direct Coombs test, an autoimmune lupus-like disease was suspected. In conjunction with rash flares, he showed progressively elevated inflammatory markers, chronic anemia, and hypoalbuminemia. Extensive investigations for an infectious etiology were negative, and without isolation of any pathogens. However, the last of a series of abdominal ultrasound examinations revealed enlarged peritoneal and retroperitoneal lymph-nodes, and biopsy yielded slow-growing bacteria, identified as Salmonella typhi. Prolonged treatment with 2 antimicrobial agents resulted in resolution of skin rash and normalization of laboratory results. Conclusions: We describe an IL-12Rβ1 deficient patient with a progressive inflammatory process with a unique immune dermatological manifestation which was probably triggered by an unexpected pathogen, Salmonella typhi. This patient’s case demonstrates the need for invasive procedures to identify an infectious etiology when routine cultures and serology tests are negative. Statement of novelty: In this case report, we describe a unique presentation of infection with Salmonella typhi in a patient with IL-12Rβ1 deficiency, manifesting with bouts of leucocytoclastic vasculitis. We also report in the same patient, recurrent infection with an unusual pathogen, Kocuria kristinae. Both phenomena have not been reported in such constellation, and we believe this to be a useful and important description that could alert physicians, immunologists, and pediatricians alike to such manifestations. Further, it may help in a rapid and successful diagnosis, therefore benefiting such patients.