Malignancy; Intermittent knee pain; Petechiae bilateral lower extremities, petechial rash; Intermittent back pain; MPV high; Increased brusing, several bruises; Viral illness; Nasal congestion; Low iron saturation (5%); Persistent severe thrombocytopenia/ Consumptive thrombocytopenia; allergy; Low grade fever; bleeding symptoms; Platelet count of 8, significantly/critical low; Chronic persistent ITP; Severe fatigue, sleeping, Crushing fatigue; Falling asleep; Runny nose; This case was reported by a nurse via other and described the occurrence of thrombocytopenia in a 13-year-old male patient who received DTPa (Reduced antigen) (Boostrix) (batch number 4F99G, expiry date unknown) for prophylaxis.   Co-suspect products included MENACTRA (batch number U6745AA, expiry date unknown) for prophylaxis.   The patient's past medical history included headache (improved after eyeglasses or hydration), pneumonia (at 6 years old), iron deficiency (without anemia), idiopathic thrombocytopenic purpura and fatigue.   On 11th August 2020, the patient received Boostrix and MENACTRA. In September 2020, between 1 and 2 months after receiving Boostrix, the patient experienced fatigue and sleepiness. In May 2021, the patient experienced runny nose. On 21st May 2021, the patient experienced idiopathic thrombocytopenic purpura (serious criteria GSK medically significant). On 20th September 2021, the patient experienced platelets decreased. In August 2022, the patient experienced symptomatic bleeding (serious criteria GSK medically significant) and low grade fever. On an unknown date, the patient experienced thrombocytopenia (serious criteria GSK medically significant), neoplasm malignant (serious criteria GSK medically significant), knee pain, petechia, back pain, mean platelet volume increased, contusion, viral infection, nasal congestion, iron saturation decreased and allergy. The patient was treated with famotidine, prednisone, polysaccharide-iron complex (Iron Polysaccharide), vitamins nos (Multivitamin), eltrombopag olamine (Promacta), eltrombopag, iron (Iron Supplement), iron sucrose (Iron Sucrose Iv) and steroids nos (Steroids). On an unknown date, the outcome of the thrombocytopenia, idiopathic thrombocytopenic purpura, neoplasm malignant, symptomatic bleeding, sleepiness, runny nose, knee pain, petechia, back pain, platelets decreased, mean platelet volume increased, contusion, viral infection, nasal congestion, iron saturation decreased, low grade fever and allergy were recovered/resolved and the outcome of the fatigue was recovering/resolving.   It was unknown if the reporter considered the thrombocytopenia, idiopathic thrombocytopenic purpura, neoplasm malignant, symptomatic bleeding, fatigue, sleepiness, runny nose, knee pain, petechia, back pain, platelets decreased, mean platelet volume increased, contusion, viral infection, nasal congestion, iron saturation decreased, low grade fever and allergy to be related to Boostrix.     Additional Information: GSK receipt date: 13-FEB-2023 Reporter's comment: The patients past medical history includes iron deficiency without anemia, chronic ITP and low iron stores. The patient had history of headache and minor fatigue since pneumonia episode at 6 years old. The patient received boostrix and menactra vaccine. In September or October 2020 crushing fatigue starts and falling asleep in school, in bus, on the was to and from hockey practice and some minor bruising noted from sports and fatigue improves when pits. In Jan to April 2021 occasional increased bruising. The petechia noticed on BLE when taking of hockey skates during the season and it was from tight skates. On 20th may 2021 BLE petechia noticed after being outside in short playing and patient did the lab test in may 2021. This was after 1-2 days of allergy sniffles. The patient was presented in emergency department due to petechlae and found to had platelet of 8. The patients both thighs had dense petechiea and noticed that there were also some on patients arm. The next day patients mom took to the pediatrician who got lab work in order to evaluate. The patients had a CBC were notable for a platelet count 8 with no other cell lines significantly down. Due to that patient brought to emergency department. The earlier this week patient had 2 days of runny nose without fever. The patient did not had hematuria but had 2 blood on urinalysis at patients mom. The patient had some intermittent keen and back pain over the past couple of months but nothing sustained and all were now gone. The patients presentation was somewhat atypical for ITP given there was no overt illness preceding the petechial rash.  The history of nasal congestion over the last several days and there may had sub acute viral illness and the patient was not aware of it. The patient ferritin low normal at 30 not consistent with iron deficiency. The hemoglobin normal for age with normal MCV. The reporter was pleasure of meeting with patients mother for follow up of immune thrombocytopenia purpura. The patient was diagnosed with acute ITP on 21st May 2021 with platelet count of 8000. the patient was continued to gad severe thrombocytopenia (Platelets dropping to less than 10k) and treated with prednisone 20 mg BID for 5 days in July, August and September 2021. The patient also continued to had petechlae, increased brusing and fatigue that worsened when platelet count dropped. The patient was started promacta on 2nd Oct 2021 with initial dose 50 mg to 75 mg daily in order to maintain platelet count within goal and would experience petechia, increased brusing and a drop in platelet count with viral illnesses. The dose of promacta dose was adjusted based on count with overall best response at 50 mg. The patients hockey was on hold beginning late march and promacta dose was gradually decreased. On April 2022 promacta decreased to 37.5 mg daily and then 25 mg daily. On July 2022 platelets dropped to less than 20k and promacta increased to 50mg on 3rd Aug 2022. On August 2022 platelet count at 7k with bleeding symptoms and low grade fever. The promacta 50 mg and prednisone 20 mg bid improved platelets to 176k.  The patients platelet count remained variable and dropping rapidly. The patient also improved with resolution of his viral illness and adjustment to promacta dose and most recently brief treatment with low dose steroids. The patient was now doing well with most recent platelet count 464  29 December 2022. The patient did not had current sings and symptoms of bleeding, bruising and petechiae and had restarted hockey with increased levels of activity this year and very low threshold to check platelet counts with any mild viral symptoms. It was unknown if the reporter considered the thrombocytopenia, idiopathic thrombocytopenic purpura, neoplasm malignant, symptomatic bleeding, fatigue, sleepiness, runny nose, knee pain, petechia, back pain, platelets decreased, mean platelet volume increased, contusion, viral infection, nasal congestion, iron saturation decreased and low grade fever to be related to menactra.