Histamine is not released in acute thermal injury in human skin in vivo: a microdialysis study

Background  Animal models have shown histamine to be released from the skin during the acute phase of a burn injury. The role of histamine during the early phase of thermal injuries in humans remains unclear. Purpose  The objectives of this trial were to study histamine release in human skin during the acute phase of a standardized thermal injury in healthy volunteers. Methods  Histamine concentrations in human skin were measured by skin microdialysis technique. Microdialysis fibers were inserted into the dermis in the lower leg in male healthy volunteers. A standardized superficial thermal injury was elicited by a heating thermode (49°C) applied to the skin for 5 min. Histamine in dialysate was analyzed for up to 2 h after the injury using two different analytical methods. Results  Spectrofluorometric assay of histamine showed no histamine release in separate studies using 2-min samples over 20 min (n = 6) and 5–10-min samples over 120 min (n = 8). The histamine values were at the limits of the quantification limit of the spectrofluorometric assay. Confirmatory studies using a sensitive radioimmunoassay confirmed no histamine release within the first hour of a thermal injury (baseline 11.6 ± 1.8 nM vs. post-burn values of 14.8 ± 1.8 nM, n = 8). Conclusions  Histamine is not released in human skin during the acute phase of a thermal injury.