Early onset polyarthritis: an unusual presentation of MHC class II deficiency.

The article discusses the case of a pediatric patient with early onset polyarthritis which is an unusual presentation of major histocompatibility complex (MHC) class II deficiency. Topics discussed include the patient's presentation of multiple joint swellings and erythematous maculopapular rashes, the role of autoimmunity on the development of the arthritis, and hematopoietic stem cell transplantation as a curative option.