Thrombosis of the palmar digital vein after Oxford‐AstraZeneca COVID‐19 vaccination

Dear Editor,

In the era of COVID‐19, the distribution and administration of approved vaccines is a fundamental step to control the pandemic. Although studies of the vaccination show safety and effectiveness, concerns over possible side effects affect people’s willingness to accept the immunization and the extent of coverage. Oxford‐AstraZeneca vaccine, a chimpanzee adenoviral vector (ChAdOx1) encoding the SARS‐CoV‐2 spike protein DNA, is available worldwide but notable for the rare associated thrombotic events. ¹ Clarifying the plausible relationships among the adverse reaction helps to understand more about the vaccine. Herein, we encountered a 38‐year‐old woman who had sudden‐onset intermittent swelling pain over her right index finger 8 days after receiving her first dose of ChAdOx1 nCov‐19 (Oxford‐AstraZeneca) vaccine on the other arm. The symptom aggravated when the hand stayed in a dependent position. Mild headache and retro‐orbital pain were reported simultaneously. She denied fever, shortness of breath, chest or abdominal pain, or visual disturbance. Physical examination revealed swelling of the right index finger with a cord‐like bluish engorged vessel over the palmar side (Fig. 1). Laboratory data for complete blood count, activated partial thromboplastin time, prothrombin time, D‐dimer, and fibrinogen demonstrated no abnormalities. Tracing back her history, she had an episode of joint stiffness years ago, and blood test showed normal platelet count, ANA, lupus anticoagulant, and anticardiolipin, but a trace amount of anti‐RNP was noted. She was diagnosed with superficial venous thrombosis of the palmar digital vein. Low dose anticoagulation with Rivaroxaban 25 mg followed by 15 mg per day was started due to concerns for vaccine‐induced immune thrombotic thrombocytopenia (VITT) and potential concurrent thrombosis in other organs. The condition improved dramatically soon after treatment (Fig. 2).

Figure 1.

Cord‐like bluish change of the palmar digital vein over the right index finger, which was more swelling compared with the left side, 8 days after ChAdOx1 nCov‐19 vaccination

Figure 2.

Rapid improvement of swelling pain and less engorged vessel soon after Rivaroxaban was given

There are various reasons to explain a prothrombotic state post vaccination. VITT has been reported after the ChAdOx1 nCov‐19 vaccine ² ; however, our patient did not fulfill the definition due to the lack of thrombocytopenia. Other reasons include hypercoagulability due to subclinical autoimmunity and vessel damage secondary to abnormal immunological activation with vaccine antigens. A similar process is also seen with the influenza vaccine and COVID‐19 infection. ³ , ⁴ Our patient had a rapid response with Rivaroxaban, which was faster than the gradual improvement one might expect with conservative therapy such as with massage and compression. ² , ³

Among the constitutional symptoms which commonly appear after ChAdOx1 nCov‐19 vaccination, alertness of the thrombosis and awareness of its severity are crucial. The delayed onset around 4 to 20 days in our patient could be a hint. The more decisive findings were the bluish cord‐like engorgement of the vessel, being more prominent when the hand stayed in a dependent position and less pronounced after prolonged raising, which was typically reported in cases with thrombosis of the palmar digital vein. ² The diagnosis was straightforward based on clinical symptoms, although there was a lack of histological or radiological confirmation. Although temporally related to the vaccine, the causality cannot be established. Nevertheless, a similar presentation of digital vein thrombosis in a patient with COVID‐19 recently might imply the possible hypercoagulable state related to viral antigen. ³ Ramessur et al. presented a case of cutaneous thrombosis associated with blister and subsequent skin necrosis after Oxford‐AstraZeneca vaccination. ⁵ The entirely different clinical manifestation in our patient extended the range of atypically located thromboses associated with vaccination.

In conclusion, this is the first published case of superficial vein thrombosis after ChAdOx1 nCov‐19 vaccine. Identifying the thrombotic event and prompt intervention are important for both health care providers and patients.