Leukocytoclastic vasculitis in Child
LCV can occur in all ages and in both sexes. It is more commonly found in adults, but up to 10% of cases are in the pediatric population. The clinical hallmark of LCV is palpable purpura: purpuric papules erupt symmetrically on the shins 7-10 days after an inciting factor. Other parts of the lower extremities may be involved including thighs and dorsal feet. Less frequently, the buttocks, upper extremities, and abdomen are involved. Initially, purpuric macules may be seen that give way to palpable purpura. In more advanced cases, bullae and ulcers may be seen. While the majority of cases are asymptomatic, LCV can be associated with pruritus, pain, or burning.
A variety of inciting factors have been identified, including medications (especially antibiotics, NSAIDs, and diuretics), pathogens (hepatitis viruses, human immunodeficiency virus [HIV], Epstein-Barr virus, and streptococci), malignancy, inflammatory bowel disease, or connective tissue disease (systemic lupus erythematosus [SLE], Sjögren syndrome, and rheumatoid arthritis). Exercise-induced vasculitis, also known as golfer's vasculitis, is a very rare cause of LCV. It is triggered by strenuous exercise, such as running, prolonged walking, or golfing, particularly during warm weather. Up to 50% of cases, however, have no identifiable cause and are considered idiopathic.
Pathogenically, antigen-antibody complexes bind to the endothelium. The complement cascade is subsequently activated, effecting neutrophil chemotaxis. Vessel wall damage then ensues secondary to proteolytic enzymes and reactive oxygen species released by neutrophils.
The physician will need to differentiate skin-limited LCV from systemic vasculitis and should suspect the latter if fever, myalgias, malaise, lymphadenopathy, abdominal pain, melena, hematochezia, diarrhea, hematuria, lower extremity swelling, or paresthesias are noted. The level of systemic involvement will largely influence the prognosis. Over 90% of patients with LCV limited to the skin will experience spontaneous resolution over several weeks to months.
L95.8 – Other vasculitis limited to the skin
60555002 – Hypersensitivity angiitis
Other small vessel vasculitis:
- Immunoglobulin A vasculitis (formerly Henoch-Schönlein purpura) – Acute onset of palpable purpura usually seen in children aged younger than 10 years in the lower extremities / buttocks 1-2 weeks after a respiratory infection. Fever, arthralgias, and renal and gastrointestinal involvement are commonly seen. Can occur in adults. Renal sequelae are of significant concern in these patients.
- Urticarial vasculitis (UV) – Recurrent, painful eruptions of urticarial lesions that last for more than 24 hours (assists in differentiating from typical urticaria) with or without angioedema. Fever, malaise, myalgias, and arthritis are commonly associated. UV has a strong association with autoimmune disease, such as SLE and Sjögren syndrome, and these entities should be investigated. Complement levels can predict systemic involvement; normal levels are seen with cutaneous limited disease, hypocomplementemic levels are seen with arthritis and gastrointestinal and pulmonary involvement.
- Microscopic polyangiitis – High incidence of renal involvement with associated weight loss, fever, and other systemic symptoms. Typically ANCA positive (about 10% are ANCA negative).
- Erythema elevatum diutinum – Violaceous, erythematous, or brown papules, nodules, and/or plaques, predominantly over the extensor surfaces of the body. Chronic course with spontaneous resolution after 5-10 years.
- Granulomatosis with polyangiitis – 90% have ENT symptoms including sinusitis, nasal / oral ulcerations, polychondritis, and upper airway involvement. Typically ANCA positive (about 10% of cases are ANCA negative).
- Eosinophilic granulomatosis with polyangiitis – Classic triad of allergic rhinitis, asthma, and peripheral blood eosinophilia. 40%-60% demonstrate ANCA positivity.
- Bacterial septic vasculitis or endocarditis – Asymmetrical or haphazardly widespread distribution of the purpura should alert to the possibility of a septic or embolic vasculitis.
- Disseminated fungal infection
- Gonococcemia or meningococcemia
- Rocky Mountain spotted fever
- Traumatic purpura in the setting of antiplatelet medications or anticoagulation
- Arthropod bites
- Early disseminated intravascular coagulation
- Pre-ulcerative pyoderma gangrenosum – May begin as violaceous, pustular purpura on the lower extremities, and secondary vasculitis may be seen on histopathology.