Nonbullous neutrophilic dermatosis: Sweet's syndrome, neonatal lupus erythematosus, or both?

We describe a 5-day-old infant who fulfilled the diagnostic criteria for Sweet's syndrome, and the concurrent histologic and autoantibody features supporting the diagnosis of neonatal lupus. To our knowledge, this is the youngest case of Sweet's syndrome reported in the literature. Importantly, our findings further support the hypothesis that lupus erythematosus should be considered in the differential diagnosis of a nonbullous neutrophilic dermatosis, as it may represent the initial manifestation of the disease.