Synopsis
Recognise IgA vasculitis from palpable purpura with joint, gastrointestinal and renal involvement, exclude sepsis and other small-vessel disease, detect adult nephritis and bowel emergencies, and organise supportive, organ-specific and long-term renal care.
- IgA vasculitis classically combines non-thrombocytopenic palpable purpura, usually on dependent legs or buttocks, with arthralgia or arthritis, abdominal pain and renal abnormality.
- Check observations, full blood count and platelets, coagulation, creatinine, electrolytes, albumin, CRP, urinalysis, microscopy, ACR or PCR and blood pressure at presentation.
- A normal platelet count helps distinguish vasculitic purpura from thrombocytopenic bleeding but does not exclude meningococcal sepsis or DIC early.
Key red flags
Non-blanching rash with hypotension, fever, neck stiffness or rapid progression requires immediate meningococcal and sepsis treatment before vasculitis classification.
Colicky pain, vomiting, occult or overt bleeding and bowel-wall oedema can precede purpura and may progress to intussusception.
Investigation priorities
Distinguish non-thrombocytopenic vasculitis from platelet, DIC and microangiopathic bleeding disorders.
Management branches
Palpable non-blanching rash occurs with joint, abdominal or urinary symptoms.
- Assess sepsis physiology first, then map rash, joints, abdomen, oedema, scrotum, pressure and urine and review infection and medicines.
- Obtain blood count, platelets, coagulation, renal, albumin, inflammatory markers, microscopy and quantitative protein.
Key medicines
ParacetamolUse 500 mg–1 g orally up to four times daily when required, at least four hours apart, maximum 4 g in 24 hours, reducing the maximum for low body weight, liver risk or frailty.
Prednisolone for severe abdominal or joint diseaseAfter surgical and infectious emergencies are excluded, specialists may use 1 mg/kg orally once daily, commonly up to 60 mg/day, for one to two weeks followed by a taper based on response.