IgA Vasculitis in an Adult Linked to Cryptosporidium and Giardia Co-Infection: A Comprehensive Case Study.

BACKGROUND Immunoglobulin A (IgA) vasculitis is a small-vessel vasculitis characterized by the deposition of IgA immune complexes primarily in the skin, kidneys, and gastrointestinal tract. While it predominantly affects children, cases in adults are associated with more severe manifestations. Evidence suggests that infectious triggers play a pivotal role in its etiology. Often, it follows a self-limiting course and doesn't necessitate intervention. CASE REPORT We present the case of a 51-year-old man who presented with a maculopapular rash, arthralgia, and abdominal pain. An examination revealed a purpuric rash on lower extremities and abdomen. A lower extremity duplex ultrasound identified deep vein thrombosis (DVT) in the right leg. Skin biopsy of the rash confirmed the diagnosis of IgA vasculitis, demonstrating perivascular neutrophilic infiltrate and IgA complex deposition. Stool studies revealed co-infection with Cryptosporidium and Giardia. The patient was treated with a prednisone taper with significant improvement in symptoms. CONCLUSIONS This case highlights the potential role of Cryptosporidium as a trigger for IgA vasculitis. The presence of concurrent infections underscores the complex interplay between infections and the development of IgA vasculitis. The co-infection with Giardia suggests that a secondary infection may be involved, further complicating the disease's etiology. The observation of DVT suggests a possible link between IgA vasculitis and a prothrombotic state. This report serves to expand the knowledge of IgA vasculitis triggers and associated complications, guiding clinicians in diagnosing and managing similar cases while emphasizing the importance of vigilance in adults with these symptoms.

The association between adult-onset Still's disease and collapsing glomerulopathy: a case report.

BACKGROUND: Collapsing glomerulopathy, characterized by marked hypertrophy and hyperplasia of the podocytes with eventual collapse of the glomerular tuft, is an important cause of end-stage renal disease. Among the many causes of collapsing glomerulopathy, autoimmune diseases, such as systemic lupus erythematosus, have been implicated. There are also rare reports of adult-onset Still's disease, an autoinflammatory condition characterized by fever, rash, and inflammatory arthritis being associated with collapsing glomerulopathy. CASE PRESENTATION: Herein, we present a review of three published cases, and present a new case of a 15-year-old African American female patient with collapsing glomerulopathy who was diagnosed with adult-onset Still's disease 12 years later when she presented with fevers, arthralgias, sore throat, lymphadenopathy, hepatocellular injury, and elevated serum ferritin. Her collapsing glomerulopathy was initially well controlled following induction therapy with cyclosporine and prednisone and maintenance therapy with losartan. However, after developing adult-onset Still's disease, she had multiple flare-ups despite various immunosuppressive therapies and developed worsening renal function, eventually progressing to end-stage renal disease. CONCLUSIONS: Our case-based review highlights a rare but important association between adult-onset Still's disease and collapsing glomerulopathy, and postulates a possible pathophysiological link.