The UV erythema test as a model to investigate the anti-inflammatory potency of topical preparations--reevaluation and optimization of the method.
BACKGROUND
The ultraviolet (UV) erythema test is one of the most frequently used methods to investigate the anti-inflammatory potency of topical dermatological preparations in vivo.


METHODS
The following questions were addressed in four separate studies with healthy persons (skin types 2 and 3): (1) the optimal localization was determined by comparing light scales on the back, buttocks and volar forearms; (2) the optimal UV-B dose was determined by comparing the 1-fold, 1.5-fold and 2-fold minimal erythema doses (MEDs); (3) hydrocortisone and prednicarbate were evaluated as positive controls, and a sample size calculation was performed, and (4) betamethasone valerate and pimecrolimus were tested as further positive controls in the optimized study model.


RESULTS
The back proved to be the best localization for the UV erythema test. It showed a good correlation between the light scale and the test areas. The 1.5-fold MED was the best irradiation dose. In contrast to prednicarbate and betamethasone valerate, hydrocortisone was a rather weak positive control. However, when the sample size was > or = 40 subjects, significant results were also obtained with hydrocortisone. Pimecrolimus was not effective in the UV erythema test.


CONCLUSIONS
The UV erythema test should be performed on the back with at least 40 subjects using the 1.5-fold MED. It may be useful to include a potent corticosteroid, such as prednicarbate or betamethasone valerate, in addition to hydrocortisone. The UV erythema test seems to be suitable only for substances with corticosteroid-like effects, since in this test model the calcineurin inhibitor pimecrolimus was not effective.
Jocher
A
A
Universitäts-Hautklinik, Albert Ludwigs-Universität Freiburg, Germany.
Kessler
S
S
Hornstein
S
S
Schulte Mönting
J
J
Schempp
C M
CM
D000287:Administration, Topical; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001415:Back; D001624:Betamethasone Valerate / Q000627:therapeutic use; D065095:Calcineurin Inhibitors; D004341:Drug Evaluation / Q000379:methods; D004890:Erythema / Q000188:drug therapy* / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000627:therapeutic use; D008297:Male; D011239:Prednisolone / Q000031:analogs & derivatives / Q000627:therapeutic use; D012867:Skin / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects; D016559:Tacrolimus / Q000031:analogs & derivatives / Q000627:therapeutic use; D014466:Ultraviolet Rays
D000893:Anti-Inflammatory Agents; D065095:Calcineurin Inhibitors; C117268:pimecrolimus; D001624:Betamethasone Valerate; D011239:Prednisolone; C035287:prednicarbate; D006854:Hydrocortisone; D016559:Tacrolimus