Immunoglobulin A vasculitis in Adult
IgAV is seasonal, with most childhood cases occurring during fall and winter. In adults, cases can also occur in summer months. Episodes can often be preceded by an upper respiratory infection.
IgAV is characterized clinically by palpable purpura, abdominal pain, arthritis, and hematuria. Adults are more likely to have joint symptoms and renal dysfunction. Children are more likely to have fevers and abdominal pain. There are prodromal symptoms of malaise, headache, and arthralgias. An individual episode may persist for 3-6 weeks, with recurrences in many patients.
Severe abdominal pain, vomiting, hematemesis, diarrhea, and hematochezia may indicate gastrointestinal involvement in 50%-75% of patients. An involved inflamed and edematous bowel may be accompanied by appendicitis, ileus, and infarction. Intussusception and bowel perforation are rare in adults.
Joint abnormalities may accompany the eruption with severe pain and sometimes swelling, warmth, and tenderness. Ankles and knees are most often involved; symptoms are often transient and migratory.
Renal involvement is common but is usually self-limited, with only a fraction of patients progressing to chronic renal failure or end-stage renal disease; these patients often have baseline renal dysfunction. The risk of renal failure is higher in adult patients and in those presenting with nephrotic or nephritic syndrome.
D69.0 – Allergic purpura
191306005 – Henoch-Schönlein purpura
Differential Diagnosis & Pitfalls
- Other small vessel – Causes include infections, drugs, connective tissue diseases, and malignancies.
- – Initially presents with palpable purpura over extensor surfaces that later become fibrotic.
- – Consists of nonblanchable macules with no associated vessel inflammation.
- – Presents with erythematous, targetoid plaques most commonly acrally distributed.
- Connective tissue diseases – Have associated photosensitivity, additional antibody abnormalities, and are unlikely to be self-limited.
- – May result in purpura fulminans characterized by necrotic, nonblanchable palpable purpura on predominantly acral areas; patients are more ill.
- (DIC) – Patients are more systemically ill and present with petechiae (nonblanchable, nonpalpable macules).
- Endocarditis – Can present with characteristic Osler nodes and Janeway lesions.
- – Presents like DIC with petechiae.
- – Has palpable purpura commonly in the setting of hepatitis C.
- Rickettsial infections – Have characteristic purpura on the hands and feet, and patients are systemically ill.
Drug Reaction Data