Abnormalities of cutaneous microcirculation in atopic eczematics.

There are signs of abnormal microcirculation in atopics, yet reliable methods for its non-invasive measurement are scarce so far. Since the phenomenon of dermographism (D) elicited by blunt stroking of the skin reflects the functional response of cutaneous vessels to pressure, we studied the haemodynamics of D using laser-Doppler microfluxometry (LDF) and infrared thermography (IR-TH) in patients with atopic eczema (n = 23) and in healthy controls (n = 21) under standardized investigative conditions. Only in-patients not treated with corticoids were selected. LDF values showed a marked reduction in the intensity of hyperaemia in the patients as compared with the controls, according to the visual degree of the dermographic blanching effect (white, delayed white, indifferent; pink). A reduction of the radiating skin temperature vis-à-vis the controls was measured by IR-TH. These results yield evidence that dermographic pallor of atopic skin depends on the strength of local vasoconstriction, possibly including altered blood flow in cutaneous shunt vessels.