Table 1. Stage theory of the progression of cutaneous hypersensitivity reactions to bites from hematophagous insects.
| Stage | Immediate reaction | Delayed reaction |
|---|---|---|
| 1 (naive) | – | – |
| 2 | – | + |
| 3 | + | + |
| 4 | + | – |
| 5 (tolerance) | – | – |
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