Classification Tree for Hypersensitivity Vasculitis
HSV subsets
7. Purpura; history
of medication at disease onset
6. Purpura; no history
of medication at disease onset; age >16 at disease onset
4. Maculopapular rash
and biopsy demonstrating eosinophils in a venule or arteriole; no purpura
2. Biopsy demonstrating
granulocytes in the wall of a venule or arteriole; absence of purpura and
maculopapular rash
Non-HSV subsets
5. Palpable purpura
without medication at disease onset, age ≤16 at disease onset
1. No purpura or maculopapular
rash; no granulocytes in vessel wall
3. Maculopapular rash;
no purpura; no eosinophils in venule or arteriole
* The
subset numbers also appear below the subset boxes in Figure 1. The classification
tree yields a sensitivity of 78.5% and a specificity of 78.7%. See Table 3 for
definition of criteria.