Case Presentation: A 28 year-old unvaccinated man with a history of Hodgkin’s lymphoma in remission presented with thrombocytopenia. Six weeks ago, he was exposed to COVID-19 and developed cough and rhinorrhea. He was not tested but started taking hydroxychloroquine and azithromycin. Three weeks prior to admission, he began noticing mucosal bleeding. One week prior to admission, he presented to a local hospital and was found to have petechiae and platelet count of 1,000 with the remainder of his CBC within normal limits. COVID-19 nasopharyngeal PCR was negative. He was started on dexamethasone. Bone marrow biopsy revealed megakaryocytes without recurrence of lymphoma. He was transferred to our hospital for refractory thrombocytopenia. On admission, the patient’s platelet count was 1,000. He was diagnosed with presumed COVID-19 induced immune thrombocytopenia (ITP). His COVID-19 IgG was positive, suggesting a prior infection. Other viral studies including Hepatitis C and HIV were negative. He received platelet transfusions with only small transient increases in platelets (Figure 1). He underwent a variety of treatments including glucocorticoids, IVIG, rituximab, and eltrombopag. After about 1 month, he was discharged with a platelet count of 92,000.

Discussion: ITP is caused by autoimmune destruction of platelets leading to severe thrombocytopenia. It can occur spontaneously or in association with other conditions such as systemic lupus erythematosus, chronic lymphocytic leukemia, HIV, hepatitis C, cytomegalovirus, and Helicobacter pylori (Figure 2).(1) Drug-induced immune thrombocytopenia can be caused by a variety of agents, notably beta-lactam antibiotics, phenytoin, trimethoprim-sulfamethoxazole, vancomycin, and quinine.Recently, COVID-19 has been implicated in triggering ITP in both adults and children.(2,3,4,5) In a systematic review of 45 patients with presumed ITP due to COVID-19, the median days from onset of COVID-19 symptoms to ITP was 13, similar to the time course in our patient.(6) Seven percent of patients in the study did not have COVID-19 symptoms but tested positive for the virus, which underscores the need for COVID-19 testing in all patients presenting with ITP. The American Society of Hematology guidelines recommend either dexamethasone 40mg daily for 4 days or prednisone 0.5-2.0 mg/kg daily for 14-28 days as first-line for new-onset ITP.(7) The recommended threshold for treatment in patients who are asymptomatic or have minor bleeding is a platelet count <30,000 For patients without significant bleeding or comorbidities and a platelet count >30,000, observation is recommended. There is little data comparing second-line treatments for ITP. IVIG can be helpful in acutely elevating platelets in the bleeding. The American Society of Hematology guidelines recommend eltrombopag, romiplostim, rituximab, and splenectomy as acceptable treatments for thrombocytopenia refractory to glucocorticoids at 3 months. These guidelines emphasize the need for shared decision-making with patients, weighing potential risks and benefits. It can take weeks to months to see a response to treatment in severe cases.

Conclusions: COVID-19 can cause serious side effects including ITP, highlighting the need for continued vaccination and exposure mitigation. A new diagnosis of ITP warrants COVID-19 testing as it may occur in asymptomatic patients. Treatments for ITP include removal of offending drugs, steroids, IVIG, rituximab, thrombopoetin receptor agonists, and splenectomy.

IMAGE 1: Figure 2. Immune Thrombocytopenia (ITP) classification. Types of ITP as well as the most common offending drugs and associated conditions are indexed.

IMAGE 2: Figure 1. Platelet counts and treatments throughout the patient’s hospitalization.