Hyper IgD Syndrome Presenting as Sweet's Syndrome in a 6 week old Infant

Abstract

Abstract: Sweet’s Syndrome, also known as acute febrile neutrophilic dermatosis, is a rare condition with poorly defined immunopathogenesis that may be idiopathic or may be associated with ongoing inflammatory illness derived from infectious, malignant, or autoimmune conditions. It is characterized by the abrupt onset of rash with erythematous or violaceous papules or plaques along with fever and increased serum inflammatory markers. It is an uncommon condition in the pediatric population and affects mostly adults in the 3rd through 5th decade of life. We describe a case of Sweet’s Syndrome in an infant who subsequently was found to have mutations in the mevalonate kinase (MVK) gene, the underlying mutation for Hyper IgD syndrome (HIDS). This case exemplifies the phenotypic variation of mutations in MVK, and is the first described presentation of HIDS as Sweet’s Syndrome. Furthermore, this case implicates the IL-1 pathway in HIDS as the patient had rapid recovery of serum iron levels and CRP after initiation of the IL-1 receptor antagonist, anakinra.