Flare responses of atopic eczema patients analysed with true colour images.
OBJECTIVE
Attenuated flare responses of atopic eczema (AE) patients to histamine are well documented, but their origin is still unknown.


METHODS
Here we studied the development of erythema after histamine iontophoresis in 12 AE patients and 12 healthy volunteers by means of a RGB-camera for recording true colour images.


METHODS
10 mg cetirizine or placebo was administered orally 3 h before the experiment in a crossover design.


RESULTS
The flare reaction was found to develop after termination of histamine iontophoresis in two phases: a first phase lasting 1-2 min in which the flare increased by about 10 mm2/s and a second phase lasting another 10-15 min characterized by a slower growth in the range of 1 mm2/s.


CONCLUSIONS
Flare size was diminished in AE patients, mainly due to a slower or absent growth in the second phase. Oral application of the H1-antagonist cetirizine (Zyrtec) reduced the flare reaction in both groups of volunteers significantly, indicating that the reaction is dependent on the activation of chemosensitive nerve fibres via H1-receptors.
Rukwied
R
R
Department of Dermatology, University of Erlangen-Nürnberg, Germany.
Nischik
M
M
Forster
C
C
Heyer
G
G
Handwerker
H O
HO
D000328:Adult; D017332:Cetirizine / Q000627:therapeutic use; D018592:Cross-Over Studies; D003876:Dermatitis, Atopic / Q000150:complications*; D004311:Double-Blind Method; D004890:Erythema / Q000139:chemically induced* / Q000473:pathology / Q000517:prevention & control; D005260:Female; D006632:Histamine / Q000008:administration & dosage*; D006634:Histamine H1 Antagonists / Q000627:therapeutic use; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007478:Iontophoresis; D007700:Kinetics; D008297:Male; D014741:Video Recording
D006634:Histamine H1 Antagonists; D006632:Histamine; D017332:Cetirizine