Synthetic marijuana "K2" induced ITP.

Immune thrombocytopenia (ITP) is a heterogeneous disease which can be primary or secondary due to other conditions such as drugs. CB2 receptors (CB2R) also have a role in the ITP pathogenesis as CB2 receptor gene (CNR2) polymorphisms are associated with chronic immune thrombocytopenia and autoimmune diseases. K2 is synthetic marijuana which acts on cannabinoid receptors that are found on immune cells and thrombocytes. Here, we present a case who presented with ITP secondary to K2 usage and was successfully treated with 1 mg/kg prednisolone. This is the first ITP case in the literature due to K2. It is important in the era of the new drugs development of the CB2R mimetics.