Scar tissue after vesicular eruptions is more painful than adjacent skin.
Pigmentation changes indicate thermal sensory deficits.
Increased pain on exposure to heat is more common than on exposure to cold. The border zone usually exhibits less severe allodynia. Rapid titration of TCAs produces a more rapid pain relief response. Because lower doses are used than when treating depression, adverse effects are a minimal concern. Amitriptyline, desipramine, and nortriptyline have all been used in this setting.