RESUMO
BACKGROUND: Skin rubor, or reddish discoloration on skin, is a sign of irritation. Physiologically it involves temporary vasodilation and hyperaemia in tissue, and is diagnosed by the visible characteristics. PURPOSE: Bioelectrical impedance analysis (BIA) was tested to estimate skin rubor. METHODS: Five healthy women (22-25 years) participated in the experiments. Four were ethanol patch test (EPT)-positive; one was negative. A skin rubor was developed on the subjects' left forearm by temporary vasodilatation, which was caused by a dermal inflammation reaction due to application of ethanol to the skin. BIA was then conducted for the skin rubor and the intact skin using a lock-in amplifier with a frequency range of 0.1Hz-10kHz. The impedance changes due to vasodilatation of capillary were evaluated. RESULTS: The resistance of the skin rubor was found to decrease to almost 90% of the resistance and 87% of the reactance of the intact skin in the EPT-positive subjects. There was no impedance change in the EPT-negative subject. Through these experiments, skin rubor could be distinguished from intact skin based on the electrical impedance. CONCLUSION: Skin rubor could be identified based on the bioelectrical impedance. This method would be used for various skin diagnoses due to simplicity and reliability of BIA.
