Leukocytoclastic vasculitis (LCV) represents the deposition of immune complexes in small blood vessels with subsequent vessel damage and blood extravasation. Nonblanching, purpuric macules and erythematous papules frequently coalesce into plaques (“palpable purpura”). The lower extremities and dependent areas of the back and buttocks are most frequently involved. Pruritus can be significant. Vesicles, ulcers, and necrosis may be seen within the purpuric lesions. A crop of lesions appear over a few days and usually resolve with hyperpigmentation over 4 to 6 weeks. Associated symptoms may include fever, arthralgias, myalgias, and malaise.
LCV is associated with many chronic diseases (connective tissue diseases, malignancies, and inflammatory bowel disease), medications (cephalosporins, penicillins, sulfonamides, minocycline, thiazides, allopurinol, phenytoin, NSAIDs, oral contraceptives, antithyroid agents), infections (group A β-hemolytic streptococci, mycobacterium leprae, viral hepatitis, HIV), and idiopathic subtypes (Henoch-Schönlein purpura [HSP], acute hemorrhagic edema of childhood, urticarial vasculitis).
HSP is a unique form of LCV with palpable purpura of the lower extremities and buttocks. Occasionally, the lesions may be found on the upper extremities, trunk, and face. A recent respiratory infection, arthralgias, abdominal pain, and hematuria are commonly noted. Renal vasculitis can occur in up to 40%, but chronic renal impairment occurs in only 2%. Adults have a tendency to have necrotic lesions (rare in children), as well as a higher incidence of renal impairment.
Urticarial vasculitis presents with burning and painful urticaria. The lesions are distinguished from common urticaria by their persistence (lasting over 24 hours), associated purpura, and resolution with hyperpigmentation. Urticarial vasculitis can be seen with connective tissue disease, viral infections, medications (NSAIDs, fluoxetine, cocaine, and others), and malignancies.
Management and Disposition
Recognition that a diverse group of diseases can trigger LCV is the first step. Evaluation for systemic symptoms (fever or other signs of infection, hematuria, gastrointestinal bleeding, and neurologic symptoms) requiring admission and appropriate consultation should be undertaken. Most cases are self-limited and only require supportive care (rest, elevation, antihistamines, and analgesics). Systemic symptoms require admission and consideration of corticosteroids and other immunosuppressants. Dermatologic referral for mild LCV cases is indicated and, if systemic symptoms present, consultation may help expedite the diagnosis. HSP and urticarial vasculitis require dermatologic consultation as well as appropriate specialty consultations.
LCV affects all ages and has equal incidence in males and females. The etiologies are often idiopathic, but scrutinize each patient for associated diseases and medicine exposures.
Renal involvement associated with HSP is more common in adults and lesions above the waist.
Leukocytoclastic Vasculitis. Lower extremities with erythematous papules and dorsal foot with erythematous plaques. If you were to run your finger across these lesions, they would be raised and not blanch. (Photo contributor: Lawrence B. Stack, MD.)
Leukocytoclastic Vasculitis. Acute necrotic LCV. (Photo contributor: J. Matthew Hardin, MD.)
Leukocytoclastic Vasculitis. Note the erythematous papules beginning to coalesce. These would not blanch with pressure. (Photo contributor: J. Matthew Hardin, MD.)
Henoch-Schönlein Pupura. Note the classic acral distribution of HSP (both upper and lower extremities—raising concern for renal involvement). (Photo contributor: Kevin J. Knoop, MD, MS.)
Urticarial Vasculitis. Urticarial plaques present for over 24 hours. (Photo contributor: J. Matthew Hardin, MD.)