Macroscopic Fluorescence and Protoporphyrin IX
in Psoriasis and Actinic Keratosis
Title: Correlation Between Macroscopic Fluorescence
and Protoporphyrin IX Content in Psoriasis and Actinic Keratosis
Following Application of Aminolevulinic Acid.
Authors: Smits T., et al.
Publication: J Invest Dermatol. 2005 Oct;125(4):833-9.
5-aminolevulinic acid (ALA) is metabolized by the body into porphyrin
(FDAP) and protoporphyrin IX (PPIX), which fluoresces when illuminated
by light of a certain wavelength. In this study, the authors investigated
whether skin lesions in psoriasis and actinic keratosis (AK) have
accumulation in FDAP and PPIX.
To do this, they took skin lesion and healthy skin, and incubated
them in a solution of 20% ALA for 3 hours. They found that PPIX
levels in both psoriasis (4.12 + 0.19 pmol/ml) and AK lesions
(1.96 + 0.24) were significantly higher than in healthy skin,
especially in psoriatic lesion. The levels of FDAP were also higher
in psoriatic (1.77 + 0.06) and AK lesions (1.37 + 0.07).