This case was reported in a literature article and described the occurrence of thrombotic thrombocytopenic purpura in a 40-year-old female patient who received Influenza vaccine. Concurrent medical conditions included hypertension, hyperlipidemia and type II diabetes mellitus. Concomitant products included ZOCOR, Metformin, lisinopril, hydrochlorothiazide and TOPROL XL. On an unknown date, the patient received influenza vaccine (unknown). On an unknown date, 14 days after receiving Influenza vaccine, the patient experienced thrombotic thrombocytopenic purpura (serious criteria hospitalization and GSK medically significant), acquired von Willebrand's disease (serious criteria GSK medically significant), cough, influenza-like symptoms, fatigue, headache, dizziness, abdominal pain, confusion, urine discoloration, impaired work ability, diarrhea, shortness of breath and increased tendency to bruise. The patient was treated with prednisone. On an unknown date, the outcome of the thrombotic thrombocytopenic purpura, acquired Von Willebrand's disease, fatigue, headache, dizziness, abdominal pain, confusion, urine discoloration, impaired work ability, diarrhea, shortness of breath and increase tendency to bruise were unknown and the outcome of the cough and influenza-like symptoms were recovered/resolved. The reporter considered the thrombotic thrombocytopenic purpura, acquired von Willebrand's disease, cough, influenza-like symptoms, fatigue, headache, dizziness, abdominal pain, confusion, urine discoloration, impaired work ability, diarrhea, shortness of breath and increased tendency to bruise to be probably related to Influenza vaccine. Additional information received: This case was reported in a literature article and it described the occurrence of thrombotic thrombocytopenic purpura in a 40-year-old female patient who had received an unspecified influenza vaccine (manufacturer unknown). Her concomitant medical conditions included hypertension, hyperlipidemia and type 2 diabetes for which she was taking the following concomitant medication: ZOCOR, Metformin, Lisinopril/HCTZ, PREVACID and TOPROL XL (doses not provided). No further information on the patient's medical or family history, concurrent medical conditions or concomitant medication was provided. On an unspecified date, the patient received a dose of an unspecified influenza vaccine at a local pharmacy (administration route and site unspecified; dosage unknown; batch number not provided). On an unspecified date, "immediately" after the vaccination according to the authors, she developed cough and flu-symptoms that lasted for 1 week. The following week, she started to experienced fatigue, headaches, dizziness, abdominal pain, confusion and dark urine that prevented her from being able to complete to her tasks at work. She was admitted to a medical facility complaining of diarrhoea and a feeling of severe lightheadedness 2 weeks after the vaccination. Upon initial examination she was found to be short of breath and to have increasing bruising; although her observations were within normal limits and the rest of the examination was unremarkable according to the authors. She was diagnosed with acute thrombotic thrombocytopenic purpura by autoantibody-mediated ADAMTS-13 deficiency. She was commenced on plasmapheresis for treatment; but she had an anaphylactic reaction during the fourth round. This was a serious case as it required hospitalisation. On admission she had the following abnormal results: platelet count was 10,000; lactate dehydrogenase was 800; fibrinogen level was 419 and there were schistocytes on an peripheral smear. Her level of ADAMTS-13 was 3%. Other investigations, including direct Coombs test, human immunodeficiency virus and hepatitis panel were negative. She was reported to have a normal creatinine level. At the time of discharge her platelet level was above 200. Initial treatment for the thrombotic thrombocytopenic purpura consisted of 4 rounds of plasmapheresis but she continued to have recurrent thrombocytopenia and experienced an anaphylactic reaction during the fourth round. In view of this, she was started on high dose prednisone (not specified) that made her able to tolerate 2 additional rounds of plasmapheresis with a reported good response. The outcome of the events was resolution of all the symptoms by the time of discharge and the platelet count had improved to over 200. The authors believed that the vaccine had triggered the event. The authors concluded that "the patient was diagnosed with acute thrombotic thrombocytopenic purpura caused by autoantibody-mediated ADAMTS-13 deficiency. Thrombotic thrombocytopenic purpura is typically diagnosed based on a pentad, including microangiopathic hemolytic anemia with schistocytes on smear, fever, renal dysfunction, neurological signs, and thrombocytopenia. Thrombotic thrombocytopenic purpura can be familiar or can occur due to various secondary causes, including viral or bacterial infection, pregnancy, autoimmune disease, organ transplant, cancer, or immunosuppression. The acquired deficiency of von Willebrand factor cleaving protease, ADAMTS-13, has been associated with the diagnosis of thrombotic thrombocytopenic purpura. Acquired thrombotic thrombocytopenic purpura can occur due to inhibitory antibodies against the von Willebrand factor cleaving protease. Our patient's clinical signs and symptoms as well as laboratory data all supported the diagnosis of thrombotic thrombocytopenic purpura. After an extensive work-up, the development of our patient's thrombotic thrombocytopenic purpura was attributed to the influenza vaccine. While vaccination is an important part of preventive medicine, vaccines have been associated with autoimmune events in rare instances. In our particular patient, we believe that our patient acquired thrombotic thrombocytopenic purpura since the vaccine produced anti-ADAMTS immunoglobulin inhibitor. There are minimal case reports in the literature of thrombotic thrombocytopenic purpura following administration of the flu vaccine, and this is known as a rare side effect. However, our patient responded to plasmapheresis and corticosteroids, the known treatments for acquired thrombotic thrombocytopenic purpura, and her platelet count recovered. In conclusion, we present a patient with thrombotic thrombocytopenic purpura following the flu vaccine. The patient initially presented with various mysterious symptoms after the flu vaccine and was ultimately found to have thrombotic thrombocytopenic purpura. Signs and symptoms of thrombotic thrombocytopenic purpura can be varied and subtle, but it is important to remain alert to them. The association with the influenza vaccine is seen in few case reports in literature but demonstrates the rare side effects of vaccines".