They can also result from autoimmune disorders, such as lupus or rheumatoid arthritis, bone marrow disorders such as leukemia, inflammation of the veins, as a side effect of certain medications, viral infections, such as EBV or
Dengue and septicemia or infection in
blood. A
complete blood count, urine examination and a blood culture may be required to reach a diagnosis.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!