IgA vasculitis, also known as Henoch-Schönlein purpura, is a systemic hypersensitivity vasculitis caused by immune complex deposition in small blood vessels, including the renal glomeruli. It was first described in 1837 by Johann Lukas Schönlein and later named by Eduard Henoch in 1874. The condition is characterized by skin purpura, arthritis, abdominal pain, and renal involvement. IgA nephropathy is the most common cause of primary glomerulonephritis globally. Diagnosis is typically based on IgA deposition in small blood vessels and the renal glomeruli. The article reviews the history, classification, epidemiology, presentation, and diagnosis of IgA vasculitis and nephropathy, as well as disease associations and triggers, including infections, vaccines, and therapeutic agents. It also highlights future approaches to improve diagnosis and clinical management. IgA vasculitis is more common in children aged 3-15 years, with a mean age of 6 years, and less commonly in adults. The global incidence is estimated at 3-27 per 100,000. Risk factors include upper respiratory tract infections, vaccinations, and certain drugs. In adults, the condition is more likely to involve the kidneys, and there is a need for investigation for solid-organ malignancy in those without known triggers. The clinical presentation in children is typically self-limiting, with palpable purpura, arthritis, abdominal pain, and renal disease. In adults, the presentation is similar, but renal involvement is more severe. Diagnosis of IgA vasculitis involves clinical findings, such as palpable purpura, arthritis, abdominal pain, and renal disease, and histopathological examination showing leukocytoclastic vasculitis in the skin, major organs, and renal glomeruli. Immunohistochemistry and immunofluorescence can identify IgA immune complexes. The pathogenesis involves immune-mediated hypersensitivity, with factors such as infections, vaccines, and genetic predispositions playing a role. Recent studies have identified potential biomarkers for diagnosis and treatment. Future research aims to improve diagnosis, management, and understanding of IgA vasculitis. New developments in vaccines and therapeutic agents for malignancy and other chronic diseases may contribute to the incidence and global public health challenge of IgA vasculitis. Current guidelines emphasize the importance of early diagnosis and appropriate treatment, including corticosteroids, ACE inhibitors, and maintenance therapy. The article concludes that further studies are needed to improve the prevention and management of IgA vasculitis and nephropathy.IgA vasculitis, also known as Henoch-Schönlein purpura, is a systemic hypersensitivity vasculitis caused by immune complex deposition in small blood vessels, including the renal glomeruli. It was first described in 1837 by Johann Lukas Schönlein and later named by Eduard Henoch in 1874. The condition is characterized by skin purpura, arthritis, abdominal pain, and renal involvement. IgA nephropathy is the most common cause of primary glomerulonephritis globally. Diagnosis is typically based on IgA deposition in small blood vessels and the renal glomeruli. The article reviews the history, classification, epidemiology, presentation, and diagnosis of IgA vasculitis and nephropathy, as well as disease associations and triggers, including infections, vaccines, and therapeutic agents. It also highlights future approaches to improve diagnosis and clinical management. IgA vasculitis is more common in children aged 3-15 years, with a mean age of 6 years, and less commonly in adults. The global incidence is estimated at 3-27 per 100,000. Risk factors include upper respiratory tract infections, vaccinations, and certain drugs. In adults, the condition is more likely to involve the kidneys, and there is a need for investigation for solid-organ malignancy in those without known triggers. The clinical presentation in children is typically self-limiting, with palpable purpura, arthritis, abdominal pain, and renal disease. In adults, the presentation is similar, but renal involvement is more severe. Diagnosis of IgA vasculitis involves clinical findings, such as palpable purpura, arthritis, abdominal pain, and renal disease, and histopathological examination showing leukocytoclastic vasculitis in the skin, major organs, and renal glomeruli. Immunohistochemistry and immunofluorescence can identify IgA immune complexes. The pathogenesis involves immune-mediated hypersensitivity, with factors such as infections, vaccines, and genetic predispositions playing a role. Recent studies have identified potential biomarkers for diagnosis and treatment. Future research aims to improve diagnosis, management, and understanding of IgA vasculitis. New developments in vaccines and therapeutic agents for malignancy and other chronic diseases may contribute to the incidence and global public health challenge of IgA vasculitis. Current guidelines emphasize the importance of early diagnosis and appropriate treatment, including corticosteroids, ACE inhibitors, and maintenance therapy. The article concludes that further studies are needed to improve the prevention and management of IgA vasculitis and nephropathy.