[1] Non-infectious causes include haemolytic disease of the newborn, hereditary spherocytosis, twin-to-twin transfusion syndrome and recombinant erythropoietin administration.

[1] Some types of cancers can cause it such as rhabdomyosarcoma, extrosseal Ewing sarcoma, Langerhans cell histiocytosis, congenital leukaemia and neuroblastoma.

[1] Conditions that may appear similar include hemangiopericytoma, blue rubber bleb nevus, hemangioma and glomangioma.

[3] Blueberry muffin lesions in the neonate indicate the prolongation of dermal extramedullary hematopoiesis outside of the gestational period.

Blood disorders, such as hereditary spherocytosis and hemolytic disease of the newborn, that increase extramedullary hemotopoeisis can also cause a blueberry muffin baby.

It is also possible that a neonate with the blueberry muffin rash can have an underlying malignancy such as metastatic neuroblastoma and congenital leukemia.

Diagnosis of the medical condition is based on a combination of clinical presentation, physical exam, and laboratory studies.

On lab studies, there may be a high anti-cytomegalovirus antibody titer, positive CMV urine culture, and thrombocytopenia.

[3] If the cause is due to hemolytic disease of the newborn or hereditary spherocytosis, the neonate will have a positive Coomb's test and unconjugated hyperbilirubinemia.

[3] There has been a documented case of the rash completely resolving following a blood transfusion to treat severe anemia in a neonate.