Nicotinate irritation was used to test the sensitivity of the skin
according to Primavera & Berardesca(17). Measurements were
performed on the inner forearm of the volunteers. No treatment
with any ointment on the tested areas was allowed
during the whole study. Nicotinate (0·25 %; 5ml/cm2) was
applied inducing an inflammation of the skin; reddening was
measured by chromametry as a value (Minolta CR 300,
Ahrensburg, Germany) before and after treatment. Erythema
intensity is given as Da value; a value after treatment minus
a value before treatment. Additionally, capillary blood flow
was determined by Laser-Doppler-Flowmetry (O2C- System;
Lea Instruments, Giessen, Germany) in the irritated area.