8-methoxypsoralen Bath Research Articles

Role of bath psoralen plus ultraviolet A in early-stage mycosis fungoides

Psoralen plus ultraviolet (UV) A (PUVA) radiation is the preferred treatment for folliculotropic mycosis fungoides (MF) and MF refractory to narrowband (NB) UVB radiation. However, systemic PUVA has many unfavorable side effects and contraindications. Bath PUVA has been found to be a suitable alternative in patients with psoriasis, but data on MF are sparse. The purpose of the study was to evaluate the effectiveness of bath PUVA in the treatment of folliculotropic MF and NB-UVB-refractory early-stage MF. The study group included 26 patients of average age 44 years attending a tertiary medical center in 2004 through 2012, 14 with folliculotropic type and 12 with NB-UVB-refractory early-stage MF who were not amenable for oral PUVA. Treatment consisted of 0.2 mg/L 8-methoxypsoralen bath 3 times weekly followed by UVA irradiation at 0.3 J/cm(2) with fixed increments every second session. A complete clinical response was achieved in 62% of patients after an average of 33 weeks and a cumulative radiation dose of 158 J/cm(2). This was a relatively small series. Bath PUVA is a good treatment option for superficial folliculotropic MF and NB-UVB-refractory early-stage MF.

Retrospective long‐term follow‐up in patients with chronic palmoplantar dermatoses after good response to bath PUVA therapy

Numerous studies have confirmed the short-term effectiveness of 8-methoxypsoralen bath PUVA therapy in patients with chronic palmoplantar dermatoses; however, little is known about long-term results. In this retrospective study we examined the long-term results in 79 patients (mean age: 48 years) with chronic palmoplantar dermatoses who were treated with bath PUVA three times a week over an 8-year period. A good clinical response (a reduction of more than 50% of the skin lesions) occurred after a mean of 23 treatments and a mean cumulative UVA dose of 39 J/cm(2) in 51 patients (65%). In 2007 a questionnaire was sent to these 51 patients to assess the long-term outcome. With bath PUVA treatment, the best results were found in patients with hyperkeratotic eczema (17/22; 77% good clinical response) followed by patients with palmoplantar psoriasis (26/41; 63%) and patients with dyshidrotic eczema (8/16; 50%). Thirty-four patients (67%) answered the questionnaire after a mean follow-up interval of 4.3 years (10-87 months). Among these patients, 36% reported an improved course of disease after PUVA therapy with reduced frequency and/or intensity of the skin rash, and 29% of patients reported continued complete clearance. 79% of our patients reported a long-term reduction in the use of topical corticosteroids during the follow-up period (mean: 4.3 years). In addition, 67% of patients reported a lasting improvement in quality of life. These data show that bath PUVA may have a long-term, beneficial influence on the course of disease in a majority of patients with recalcitrant chronic palmoplantar dermatoses.

Penetration Kinetics of 8-Methoxypsoralen after 8-Methoxypsoralen Bath Procedure with and without UVA Irradiation

Administration of 8-methoxypsoralen (8-MOP) in a dilute bath water solution is an effective therapeutic alternative for systemic application of 8-MOP, avoiding systemic side effects such as nausea and cataractogenesis. The aim of our study was to determine the epicutaneous penetration of 8-MOP in a dilute bath water solution with and without additional UVA irradiation in human skin under in vitro conditions. To simulate the PUVA bath procedure, 8 skin samples were exposed to radioactively labeled 8-MOP in a water solution. After 20 min, the test solution was removed and the skin surface was dried. Immediately after the bath procedure, 4 of the skin samples were irradiated with 0.5 J/cm² UVA. During a test period of 15 h, the 8-MOP penetration was observed. In both test groups (with and without UVA irradiation) 8-MOP permeated through all skin layers between 30 min and 1 h after application. Compared to the unirradiated skin samples, the UVA-irradiated skin samples showed a significantly slower increase and a lower maximum of 8-MOP permeation. Following our results, UVA irradiation of 8-MOP-exposed skin samples led to a significantly decreased permeation rate. This might be due to UVA-induced links between 8-MOP molecules and human DNA. In addition, we investigated the levels of radioactivity emitted by tritium-labeled 8-MOP in stratum corneum, epidermis and dermis up to 30 min after 8-MOP bath in two further test groups with and without additional UVA irradiation. The statistical analysis revealed no significant differences between these two test groups. Thus, the levels of radioactivity remained constant in the epidermis and dermis during the test period of 30 min. Since the levels of radioactivity were constant up to 30 min after UVA irradiation, a previously supposed marked loss of 8-MOP concentration might not be responsible for the rapid extinction of observed in vivo photosensitivity within 1 h after PUVA bath observed in vivo in human skin.

Assessment of minimal phototoxic dose following 8-methoxypsoralen bath: maximal reaction on average after 5 days.

An essential procedure before starting bath psoralen ultraviolet (UV) A (PUVA) photochemotherapy is the evaluation of the minimal phototoxic dose (MPD), which is traditionally assessed 3 days after irradiation. However, there are no controlled studies supporting the 72 h peak of bath-PUVA erythema. The aim of this study was therefore to determine the exact time course of the erythematous reaction in human skin following bath-PUVA. For this purpose, the skin of 10 volunteers was exposed to 0.5-3.0 J/cm2 UVA directly after a 20-min 8-methoxypsoralen bath (0.5 mg/L, 37 degrees C). At 24, 48, 72, 96, 120 and 144 h (1-6 days) after irradiation, the MPD and the erythema sum score (ESS) were determined in each subject. The results showed a maximal erythematous reaction on average 5 days after irradiation. The mean MPD gradually decreased from day 2 (> 3.0 J/cm2) to day 5 (mean +/- SD 1.15 +/- 0.63 J/cm2) and started to increase at day 6 (mean +/- SD 1.6 +/- 0.52 J/cm2). The mean +/- SD ESS correspondingly increased from day 2 (0 +/- 0) to day 5 (10.5 +/- 3. 7) with a decrease at day 6 (7.5 +/- 3.1) (difference between day 3 and beyond statistically significant at P < 0.05). As our study indicates a maximal erythematous reaction to the bath-PUVA up to 5 days after irradiation, the traditional MPD assessment at 3 days generates a risk of phototoxic side-effects within the phototherapy course by underestimating the phototoxic effect in some patients. These findings contribute towards a more defined understanding of the kinetics of the phototoxic reaction in bath-PUVA therapy.

Cancer incidence among Finnish psoriasis patients treated with 8-methoxypsoralen bath PUVA

Background: Long-term oral 8-methoxypsoralen (8-MOP) and UVA (PUVA) therapy increases the risk of nonmelanoma skin cancer and possibly also of cutaneous malignant melanoma. Topical application of 8-MOP PUVA induces malignant tumors in rodent skin, but little is known about its carcinogenicity in human skin. Objective: Our purpose was to investigate the carcinogenicity of 8-MOP bath PUVA in humans. Methods: This was a cohort study of 158 patients with psoriasis, for whom 8-MOP bath PUVA had been initiated during 1979 to 1992. The average number of 8-MOP bath PUVA treatments was 36 (range, 6 to 204) and the mean cumulative UVA dose was 92 J/cm 2 (range, 3 to 884 J/cm 2) by the end of 1995. The patients were not treated with any other forms of PUVA. Cancer incidence subsequent to 8-MOP bath PUVA up to the end of 1995 was determined by linking the cohort with the records of the Finnish Cancer Registry. The standardized incidence ratios (SIR) were calculated for skin cancer and some common internal cancers, using the expected numbers of cases based on the regional cancer incidence rates. Results: There was one case of basal cell carcinoma, but no cases of other types of skin cancer. A total of 6 noncutaneous cancers were observed (SIR, 1.3; 95% confidence interval, 0.5 to 2.8). Conclusion: No association between cutaneous cancer and 8-MOP bath PUVA was found, but the statistical power of this study alone is not adequate to warrant definite conclusions. The results can be used in a meta-analysis as soon as other studies on the carcinogenicity of 8-MOP bath PUVA are published.(J Am Acad Dermatol 1999;40:694-6.)

8-Methoxypsoralen bath PUVA clears psoriasis after failure of oral PUVA

Clinical and Experimental DermatologyVolume 15, Issue 4 p. 320-320 8-Methoxypsoralen bath PUVA clears psoriasis after failure of oral PUVA P. Collins, P. Collins City of Dublin Skin and Cancer Hospital, Hume St., Dublin 2. Ireland.Search for more papers by this authorS. Rogers, S. Rogers City of Dublin Skin and Cancer Hospital, Hume St., Dublin 2. Ireland.Search for more papers by this author P. Collins, P. Collins City of Dublin Skin and Cancer Hospital, Hume St., Dublin 2. Ireland.Search for more papers by this authorS. Rogers, S. Rogers City of Dublin Skin and Cancer Hospital, Hume St., Dublin 2. Ireland.Search for more papers by this author First published: July 1990 https://doi.org/10.1111/j.1365-2230.1990.tb02103.xCitations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume15, Issue4July 1990Pages 320-320 RelatedInformation