Leukocytoclastic Vasculitis; This is a literature report for the following literature source(s):   An 81-year-old male with a past medical history of atrial fibrillation, hypertension, and hypothyroidism presented to the emergency department for evaluation of a bilateral lower extremity purpuric non-blanching rash that appeared two days prior. He had received the Pfizer-BioNTech booster vaccine against SARS-CoV-2 ten days before developing the rash. He reported having a similar rash after the second dose of the Pfizer-BioNTech COVID-19 vaccine six months before evaluation that was self-limited and resolved without further intervention. Physical examination was remarkable for purpuric 1 to 3mm macules, some barely palpable and located in the shin and anterior and medial thighs of the lower extremities. There was sparing of the abdomen, back, chest, upper extremities, and neck. Initial laboratory tests showed WBC 9.35 x 109/L, Hgb 13.3 g/dL, HCT 41.9%, Na 137 mEq/L, K 3.9 mmol/L, Cr 1.09 mg/dL, AST 18 U/L, ALT 16 U/L, CRP 9 mg/L, ESR 16 mm/hr, C3 120 mg/dL, and C4 20 mg/dL. Urinalysis was normal and without evidence of proteinuria or microhematuria. Additional laboratory tests were negative and included cANCA, pANCA, ANA, Hep C, and B serologies, syphilis screen, and Lyme antibodies. Ultrasound of the lower extremities was also performed and showed no evidence of venous thrombosis. Patient home medications included aspirin, finasteride, levothyroxine, and metoprolol tartrate. He denied the use of any new medications and any additional symptoms, including abdominal pain, vomiting, nausea, melena, hematochezia, hematuria, myalgia, arthralgia, fatigue, headache, fever, and chills. The patient was admitted to the medicine floor for further investigation of the bilateral lower extremities' purpuric rash. During hospitalization, the dermatology and rheumatology specialists evaluated the patient and recommended performing a skin biopsy. A skin biopsy was performed and showed extravasation of erythrocytes, perivascular infiltrate of neutrophils, nuclear dust, and eosinophils, consistent with LCV and negative direct immune fluorescence. The consensus decision was to treat conservatively without the use of systemic corticosteroids, or any additional treatment and the patient was discharged home. In the outpatient follow-up, the patient reported complete resolution of the rash three weeks after the symptoms first appeared, and there was no need for any further testing or treatment. Vaccines against COVID-19 represent a pivotal and effective countermeasure to control the COVID-19 pandemic. This case reveals a potential association between the administration of a COVID-19 vaccine and the development of vasculitis. This could be secondary to complement activation or autoimmunity provoked by the vaccine's SARS-CoV-2 spike protein, leading to inflammation of the cutaneous microvasculature and resulting in vasculitis. Although vasculitis may not be considered a contraindication of vaccination, further investigation is necessary to clarify the characteristics of vasculitis following COVID-19 vaccination.; Sender's Comments: Based on the information currently available, The casual association between the reported event and suspected drug cannot be completely excluded.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.,Linked Report(s) : US-PFIZER INC-PV202300024346 Same article/patient/event and different drug;