Digital fluorescence photography can assess the suppressive effect of benzoyl peroxide on Propionibacterium acnes.
BACKGROUND
Porphyrins produced by Propionibacterium acnes exhibit an orange-red fluorescence under UVA light. The amount of fluorescence can be estimated by digital fluorescence photography.


OBJECTIVE
We thought that digital fluorescence photography would be a quicker and simpler method than bacteriologic culture to demonstrate depopulation of P acnes in sebaceous follicles. We used benzoyl peroxide to bring about rapid suppression of P acnes.


METHODS
Benzoyl peroxide 10% was applied twice daily for 7 days to the faces of 9 subjects. Five subjects were untreated controls. Digital fluorescence photographs of cheek and nose, and scrub samples for quantitative recovery of P acnes from the cheek were taken at baseline, day 3, day 7 (end of treatment), and day 16 (regression phase).


RESULTS
The effect of benzoyl peroxide against P acnes was clearly demonstrated both by culture and by fluorescence photography after only 3 days. Image analysis of porphyrin fluorescence correlated well with the decrease in P acnes density from scrub cultures. No further decrease was observed at day 7 (end of therapy). Ten days later there was a return to baseline values, although in some subjects these remained lower.


CONCLUSIONS
Digital fluorescence photography is a reliable, fast, and easy screening technique to demonstrate the suppressive effect of topical antibacterial agents on P acnes.
Pagnoni
A
A
S.K.I.N. Incorporated, Conshohocken, Pennsylvania 19428, USA.
Kligman
A M
AM
Kollias
N
N
Goldberg
S
S
Stoudemayer
T
T
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001585:Benzoyl Peroxide / Q000494:pharmacology*; D005260:Female; D005453:Fluorescence; D006801:Humans; D008297:Male; D008875:Middle Aged; D010781:Photography; D011425:Propionibacterium acnes / Q000187:drug effects* / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents; D001585:Benzoyl Peroxide