Table 1.
Summary of acute hemorrhagic edema of infancy, Henoch‐Schönlein purpura, Kawasaki disease, and Sweet syndrome
| Acute hemorrhagic edema of infancy | Henoch‐Schönlein purpura | Kawasaki disease | Sweet syndrome | |
|---|---|---|---|---|
| Typical age of onset | 6 mo to 2 y | 2‐6 y | 13‐24 mo | 30‐50 y |
| Appearance of lesions | Annular and targetoid, erythematous and purpuric plaques | Urticarial papules progressing to palpable purpura | Nonspecific; morbilliform, urticarial, or scarlatiniform morphologies | Tender, erythematous papules and plaques |
| Typical location | Face, ears, distal extremities | Lower extremities, buttocks | Diffuse | Limbs, face, neck |
| Duration of individual lesions | 1‐3 wk | 5 d | Several days | 3‐9 d (with treatment) |
| Duration of rash | 1‐3 wk | 4‐6 wk | Days to weeks | 3‐9 d (with treatment); recurrence common |
| Mucous membrane involvement | No | No | Yes—lip and tongue erythema | Rarely |
| Facial or acral edema | Yes | Yes | Yes | No |
| Fever | Variable | Variable | Yes | Variable |
| Associated signs/symptoms | Malaise, irritability | Malaise, arthralgias, abdominal pain | Nonexudative conjunctivitis, cervical lymphadenopathy | Malaise, myalgias, arthralgias |
| Inciting factors | Infection, medications, immunizations | Infection, medications, immunizations | Infection | Infection, immunodeficiency, medications, malignancy |
| Pathology | Leukocytoclastic vasculitis; direct immunofluorescence typically negative | Leukocytoclastic vasculitis; direct immunofluorescence may demonstrate IgA deposition | Vasculitis with inflammatory infiltrate of neutrophils and macrophages | Dermal edema, neutrophilic infiltrate, leukocytoclasis without vasculitis |
| Type of hypersensitivity reaction | Type III | Type III | Unknown | Type IV |
| Treatment | Supportive care | Organ‐directed support of renal, GI, joint manifestations | Intravenous immunoglobulin and aspirin | Systemic corticosteroids or potassium iodide |
| Risk for severe complications | Low | Moderate | High | High |
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