Background: Limited work has been conducted on the characteristics of topical trimethylpsoralen (TMP) psoralen-UVA (PUVA) erythema.
Objective: We sought to determine the time-course and dose-response characteristics of erythema induced by topical TMP, and to compare these parameters with those for topical 8-methoxypsoralen (MOP) within patients.
Methods: After photosensitization of one forearm with topical TMP, test sites were exposed to a UVA dose series. The procedure was repeated on the other forearm using 8-MOP solution. Erythema was assessed visually and with a reflectance instrument every 24 hours for 7 days.
Results: TMP PUVA erythema followed a similar time course to 8-MOP PUVA erythema. The majority of patients were at maximal erythema at or beyond 96 hours. TMP PUVA had a significantly steeper dose-response curve at 48, 72, and 96 hours compared with 8-MOP PUVA.
Conclusion: On the basis of these data, the optimal time to read the TMP minimal phototoxic dose is 96 hours. In view of the steeper dose-response curve for TMP PUVA, a lower UVA incremental regimen should be considered compared with that for 8-MOP PUVA.
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http://dx.doi.org/10.1067/mjd.2003.419 | DOI Listing |
Molecules
November 2020
Institut für Physikalische Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
The psoralens 8-methoxypsoralen (8-MOP), 4,5',8-trimethylpsoralen (TMP) and 5-methoxypsoralen (5-MOP) find clinical application in PUVA (psoralen + UVA) therapy. PUVA treats skin diseases like psoriasis and atopic eczema. Psoralens target the DNA of cells.
View Article and Find Full Text PDFJ Eur Acad Dermatol Venereol
May 2007
Department of Dermatology, Venereology and Leprology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Background: Vitiligo is a common pigmentary disorder with great cosmetic and psychological morbidity. No treatment available is a definitive cure. Systemic psoralen and ultraviolet A (PUVA) has been the mainstay of treatment.
View Article and Find Full Text PDFJ Photochem Photobiol B
October 2004
Physiological Sciences Department, Federal University of Goiás, 74001-970 Goiânia, Brazil.
Cutaneous malignant melanoma is a very serious form of skin cancer that arises from melanocytes. Currently there is no effective treatment for metastatic melanoma so intense clinical trials are evaluating new drugs for this human malignancy. Psoralens are a group of compounds that bind to DNA in rapidly dividing cells and with ultraviolet light in the A band (UVA) cause DNA crosslinking, thereby preventing cellular division.
View Article and Find Full Text PDFJ Am Acad Dermatol
July 2003
Photobiology Unit, Department of Dermatology, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland.
Background: Limited work has been conducted on the characteristics of topical trimethylpsoralen (TMP) psoralen-UVA (PUVA) erythema.
Objective: We sought to determine the time-course and dose-response characteristics of erythema induced by topical TMP, and to compare these parameters with those for topical 8-methoxypsoralen (MOP) within patients.
Methods: After photosensitization of one forearm with topical TMP, test sites were exposed to a UVA dose series.
Br J Dermatol
June 2003
Department of Dermatology, University of Dundee, Ninewells Hospital and Medical School, Dundee, DD1 9SY, UK.
Background: In 1991, consensus guidelines recommended psoralen plus ultraviolet A photochemotherapy (PUVA) for those requiring second-line therapy for psoriasis. Narrowband (TL-01) UVB has since become more widely available, replacing the less effective broadband sources. Objectives To compare the efficacy of TL-01 UVB phototherapy and trimethoxypsoralen (TMP) bath-PUVA for chronic plaque psoriasis.
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