The specific aim of this study is to validate iontophoresis (with measurement of microvascular blood flow by laser Doppler flowmetry) in a pediatric cohort as a surrogate marker capable of reliably characterizing the normal physiologic response of the cutaneous microvasculature to histamine. In future studies laser Doppler flowmetry ultimately will be used to assess whether microvascular blood flow determined by a previously validated laser Doppler technique can be used as a reliable surrogate endpoint capable of functionally discriminating the effects of polymorphisms in the genes which are quantitatively important for histamine metabolism. The hypothesis to be proven is that histamine iontophoresis with measurement of microvascular blood flow by laser Doppler flowmetry can be used as a reliable marker to characterize the normal microvascular cutaneous response to histamine.
The hypothesis to be proven is that histamine iontophoresis with measurement of microvascular blood flow by laser Doppler flowmetry can be used as a reliable marker to characterize the normal microvascular cutaneous response to histamine.