Cryoglobulinemia is an immune complex-mediated vasculitis that predominantly affects small and medium-sized vessels. Involvement of large arteries is exceedingly rare, and pseudoaneurysm formation has rarely been described. A 44-year-old man with hepatitis C-negative cryoglobulinemic vasculitis and a mechanical aortic valve on chronic anticoagulation presented with acute left gluteal pain, near syncope, and severe anemia. Computed tomography angiography revealed a large left gluteal hematoma with active arterial extravasation. Digital subtraction angiography demonstrated a markedly enlarged superior gluteal artery supplying a large pseudoaneurysm. Distal-to-proximal endovascular embolization resulted in complete exclusion of the pseudoaneurysm and hemodynamic stabilization. This case illustrates an exceptionally rare large-artery complication of cryoglobulinemia, highlighting the potential for immune-mediated vascular injury to extend beyond the small- and medium-vessel circulation. The deep anatomic location of the superior gluteal artery can obscure early diagnosis, and delayed recognition may result in life-threatening hemorrhage. Clinicians should consider vasculitic etiologies, including cryoglobulinemia, in patients presenting with spontaneous pseudoaneurysm formation and acute hemorrhage in the absence of trauma. Early recognition and endovascular intervention can be lifesaving.

Immunoglobulin A vasculitis (IgAV) is a small-vessel immune complex-mediated vasculitis that predominantly affects children, with significantly fewer cases reported in adults. When IgAV does occur in adults, it often presents with more severe systemic involvement and worse renal outcomes compared to pediatric populations. A rare pulmonary complication of IgAV is diffuse alveolar hemorrhage (DAH). We present a case of recurrent hypoxic respiratory failure with DAH in a patient found to have biopsy proven IgAV. A man in his 60s was admitted with recurrent hypoxia following recent hospitalization for presumed pneumonia. Shortly after admission, he experienced cardiac arrest. He was intubated and had a return of spontaneous circulation. He was transferred to the ICU and underwent bronchoscopy with bronchoalveolar lavage (BAL). This revealed bloody aliquots and eosinophilia. Infectious workup was negative. Autoimmune serologies were negative. Serum inflammatory markers were elevated. Worsening kidney function raised concern for a pulmonary-renal syndrome and high-dose intravenous methylprednisolone was initiated empirically with improvement in clinical status. Renal biopsy was performed which confirmed IgA vasculitis. After seven days, the patient returned to the hospital with recurrent hypoxia and a new cavitary lung lesion. Repeat bronchoscopy with BAL was performed which was concerning for DAH. The patient was initiated on high dose IV steroids and IV cyclophosphamide. Shortly after, the patient elected for comfort care and was discharged to in-patient hospice. This case underscores the importance of timely immunosuppressive therapy and multidisciplinary care. However, prognosis remains poor in patients with severe systemic involvement.

Spondyloarthritis (SpA) is a chronic inflammatory disease characterized by axial, peripheral, and extra-musculoskeletal manifestations. Axial involvement manifests as sacroiliitis, spondylitis, and peripheral involvement in the form of arthritis, enthesitis, and dactylitis. The extra-musculoskeletal manifestations commonly include uveitis, inflammatory bowel disease, and psoriasis, in addition to rare manifestations such as aortitis, interstitial lung disease, immunoglobulin A (IgA) nephropathy, and renal amyloidosis. IgA vasculitis is an immune complex mediated vasculitis affecting small vessels with characteristic IgA deposition within the vessel walls. It primarily affects children and can affect adults in about 10% of cases. A 25-year-old male, diagnosed with nonradiographic axial SpA with bilateral sacroiliitis and enthesitis, presented with recurrent episodes of purpuric skin rash, abdominal pain, loose stools, and pedal edema. On evaluation, he had hypertension and nephritic-range proteinuria. Histopathology of skin lesions and renal biopsy revealed IgA deposits suggestive of IgA vasculitis. To date, only four case reports of SpA and IgA vasculitis have been described in the literature. In a patient with long-standing SpA, the possibility of IgA vasculitis should be considered.

Leukocytoclastic vasculitis (LCV) is a rare small-vessel vasculitis caused by immune-complex-mediated deposition on endothelial cells of dermal capillaries. Common triggers include medications, infections, autoimmune disorders, and malignancies. We present a case of a 58-year-old male who developed daptomycin-induced LCV after being treated for Methicillin-resistant Staphylococcus aureus (MRSA) endocarditis. The patient experienced painful palpable purpura on his lower extremities, which was diagnosed as LCV by skin biopsy. At the time of the biopsy, warfarin and daptomycin were discontinued, and the patient was transitioned to heparin and ceftaroline. MRSA-induced LCV was ruled out, due to negative blood cultures and adequate source control of his infection at the time of development of the skin lesions. Warfarin-induced skin necrosis (WISN) was ruled out based on histopathological findings. This case is clinically significant as it represents the first reported case of LCV associated with daptomycin use. It underscores the importance of considering the patient's history, clinical presentation, and histopathological findings to ensure prompt recognition and management of this rare drug reaction, allowing for the resolution of LCV.

Activated phosphoinositide 3-kinase delta syndrome (APDS) is an inborn error of immunity with heterogeneous clinical manifestations of infections, immune dysregulation, autoimmunity; lymphoproliferation; and malignancy. Immune complex-mediated vasculitides have not yet been described in APDS patients. Here we offer a case series of three patients with APDS who have refractory IgA vasculitis (also called Henoch-Schönlein purpura), a form of immune complex-mediated vasculitis that activates complement and attracts neutrophils, macrophages and eosinophils to cause local tissue injury. Leniolisib is an inhibitor of PI3K p110δ and an FDA-approved treatment for APDS. IgA vasculitis resolved upon treatment with leniolisib. Patients with immune dysregulation including IgA vasculitis should be screened for APDS.