Mechanisms involved in the antinociceptive and anti-inflammatory effects of xanthotoxin.

Xanthotoxin (XAT) is a natural furanocoumarin clinically used in the treatment of skin diseases such as vitiligo and psoriasis. Recent studies have also investigated its effects on anti-inflammatory, anti-cognitive dysfunction, and anti-amnesia as a guideline for clinic application. However, little is known about its effects on pain relief. Here, we tested the analgesic effects of XAT in serious acute pain and chronic pain models. For acute pain, we used hot-, capsaicin- and formalin-induced paw licking. Nociceptive threshold was measured by mechanical stimuli with von Frey filaments. For chronic pain, we injected complete Freund's adjuvant (CFA) into the mice's plantar surface of the hind paw to induce inflammatory pain. Heat and mechanical hyperalgesia were evaluated by radiant heat and von Frey filament tests, respectively. To investigate the mechanisms underlying the analgesic effect of XAT, we used calcium imaging and western blot to assess transient receptor potential vanilloid 1 (TRPV1) activity and expression in isolated L4-L6 dorsal root ganglion (DRG) neurons. Haematoxylin and eosin (HE) staining, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to examine immune cell recruitment and proinflammatory factor release from skin tissue from paw injection sites. Our results demonstrated that XAT not only reduced acute pain behaviors generated by hot, capsaicin, and formalin but also attenuated CFA-induced heat and mechanical hyperalgesia. The analgesic activity of XAT may be achieved by controlling peripheral inflammation, lowering immune cell infiltration at the site of inflammatory tissue, reducing inflammatory factor production, and therefore inhibiting TRPV1 channel sensitization and expression.

Pharmacological Properties of Bergapten: Mechanistic and Therapeutic Aspects.

Bergapten (BP) or 5-methoxypsoralen (5-MOP) is a furocoumarin compound mainly found in bergamot essential oil but also in other citrus essential oils and grapefruit juice. This compound presents antibacterial, anti-inflammatory, hypolipemic, and anticancer effects and is successfully used as a photosensitizing agent. The present review focuses on the research evidence related to the therapeutic properties of bergapten collected in recent years. Many preclinical and in vitro studies have been evidenced the therapeutic action of BP; however, few clinical trials have been carried out to evaluate its efficacy. These clinical trials with BP are mainly focused on patients suffering from skin disorders such as psoriasis or vitiligo. In these trials, the administration of BP (oral or topical) combined with UV irradiation induces relevant lesion clearance rates. In addition, beneficial effects of bergamot extract were also observed in patients with altered serum lipid profiles and in people with nonalcoholic fatty liver. On the contrary, there are no clinical trials that investigate the possible effects on cancer. Although the bioavailability of BP is lower than that of its 8-methoxypsoralen (8-MOP) isomer, it has fewer side effects allowing higher concentrations to be administered. In conclusion, although the use of BP has therapeutic applications on skin disorders as a sensitizing agent and as components of bergamot extract as hypolipemic therapy, more trials are necessary to define the doses and treatment guidelines and its usefulness against other pathologies such as cancer or bacterial infections.

Non-steroidal anti-inflammatory drugs (NSAIDs) for chronic non-cancer pain in children and adolescents.

BACKGROUND: Pain is a common feature of childhood and adolescence around the world, and for many young people, that pain is chronic. The World Health Organization guidelines for pharmacological treatments for children's persisting pain acknowledge that pain in children is a major public health concern of high significance in most parts of the world. While in the past pain was largely dismissed and was frequently left untreated, views on children's pain have changed over time, and relief of pain is now seen as important.We designed a suite of seven reviews on chronic non-cancer pain and cancer pain (looking at antidepressants, antiepileptic drugs, non-steroidal anti-inflammatory drugs, opioids, and paracetamol) in order to review the evidence for children's pain utilising pharmacological interventions.As the leading cause of morbidity in the world today, chronic disease (and its associated pain) is a major health concern. Chronic pain (that is pain lasting three months or longer) can arise in the paediatric population in a variety of pathophysiological classifications (nociceptive, neuropathic, or idiopathic) from genetic conditions, nerve damage pain, chronic musculoskeletal pain, and chronic abdominal pain, as well as for other unknown reasons.Non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat pain, reduce fever, and for their anti-inflammation properties. They are commonly used within paediatric pain management. Non-steroidal anti-inflammatory drugs are currently licensed for use in Western countries, however they are not approved for infants under three months old. The main adverse effects include renal impairment and gastrointestinal issues. Common side effects in children include diarrhoea, headache, nausea, constipation, rash, dizziness, and abdominal pain. OBJECTIVES: To assess the analgesic efficacy and adverse events of NSAIDs used to treat chronic non-cancer pain in children and adolescents aged between birth and 17 years, in any setting. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online, MEDLINE via Ovid, and Embase via Ovid from inception to 6 September 2016. We also searched the reference lists of retrieved studies and reviews, as well as online clinical trial registries. SELECTION CRITERIA: Randomised controlled trials, with or without blinding, of any dose and any route, treating chronic non-cancer pain in children and adolescents, comparing any NSAID with placebo or an active comparator. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for eligibility. We planned to use dichotomous data to calculate risk ratio and number needed to treat for one additional event, using standard methods. We assessed GRADE and created three 'Summary of findings' tables. MAIN RESULTS: We included seven studies with a total of 1074 participants (aged 2 to 18 years) with chronic juvenile polyarthritis or chronic juvenile rheumatoid arthritis. All seven studies compared an NSAID with an active comparator. None of the studies were placebo controlled. No two studies investigated the same type of NSAID compared with another. We were unable to perform a meta-analysis.Risk of bias varied. For randomisation and allocation concealment, one study was low risk and six studies were unclear risk. For blinding of participants and personnel, three studies were low risk and four studies were unclear to high risk. For blinding of outcome assessors, all studies were unclear risk. For attrition, four studies were low risk and three studies were unclear risk. For selective reporting, four studies were low risk, two studies were unclear risk, and one study was high risk. For size, three studies were unclear risk and four studies were high risk. For other potential sources of bias, seven studies were low risk. Primary outcomesThree studies reported participant-reported pain relief of 30% or greater, showing no statistically significant difference in pain scores between meloxicam and naproxen, celecoxib and naproxen, or rofecoxib and naproxen (P > 0.05) (low-quality evidence).One study reported participant-reported pain relief of 50% or greater, showing no statistically significant difference in pain scores between low-dose meloxicam (0.125 mg/kg) and high-dose meloxicam (0.25 mg/kg) when compared to naproxen 10 mg/kg (P > 0.05) (low-quality evidence).One study reported Patient Global Impression of Change, showing 'very much improved' in 85% of ibuprofen and 90% of aspirin participants (low-quality evidence). Secondary outcomesAll seven studies reported adverse events. Participants reporting an adverse event (one or more per person) by drug were: aspirin 85/202; fenoprofen 28/49; ibuprofen 40/45; indomethacin 9/30; ketoprofen 9/30; meloxicam 18/47; naproxen 44/202; and rofecoxib 47/209 (very low-quality evidence).All seven studies reported withdrawals due to adverse events. Participants withdrawn due to an adverse event by drug were: aspirin 16/120; celecoxib 10/159; fenoprofen 0/49; ibuprofen 0/45; indomethacin 0/30; ketoprofen 0/30; meloxicam 10/147; naproxen 17/285; and rofecoxib 3/209 (very low-quality evidence).All seven studies reported serious adverse events. Participants experiencing a serious adverse event by drug were: aspirin 13/120; celecoxib 5/159; fenoprofen 0/79; ketoprofen 0/30; ibuprofen 4/45; indomethacin 0/30; meloxicam 11/147; naproxen 10/285; and rofecoxib 0/209 (very low-quality evidence).There were few or no data for our remaining secondary outcomes: Carer Global Impression of Change; requirement for rescue analgesia; sleep duration and quality; acceptability of treatment; physical functioning as defined by validated scales; and quality of life as defined by validated scales (very low-quality evidence).We rated the overall quality of the evidence (GRADE rating) for our primary and secondary outcomes as very low because there were limited data from studies and no opportunity for a meta-analysis. AUTHORS' CONCLUSIONS: We identified only a small number of studies, with insufficient data for analysis.As we could undertake no meta-analysis, we are unable to comment about efficacy or harm from the use of NSAIDs to treat chronic non-cancer pain in children and adolescents. Similarly, we cannot comment on our remaining secondary outcomes: Carer Global Impression of Change; requirement for rescue analgesia; sleep duration and quality; acceptability of treatment; physical functioning; and quality of life.We know from adult randomised controlled trials that some NSAIDs, such as ibuprofen, naproxen, and aspirin, can be effective in certain chronic pain conditions.

Erythema action spectrum of topical 8-methoxypsoralen-sensitized skin re-evaluated: implications for routine clinical practice.

BACKGROUND: Published methodology used to determine psoralen plus ultraviolet A (PUVA) erythemal action spectrum does not reflect current clinical practice for psoralen sensitization. We re-evaluated the PUVA action spectrum using aqueous 8-methoxypsoralen (8-MOP) 2·6 mg L(-1) as used routinely in current clinical practice. OBJECTIVES: To determine the UVA erythema action spectrum of topical 8-MOP-sensitized normal skin. METHODS: Twenty healthy volunteers with skin phototypes I-V were recruited. Forearms were psoralen-sensitized at 37 °C for 10 min. Six UVA irradiations at 10-nm intervals between 325 and 375 nm were randomly allocated to forearm sites and were applied using a 10-nm bandwidth irradiation monochromator. The visual minimal phototoxic dose (MPD) was recorded on each site at 96 h. RESULTS: Volunteer Boston phototypes were: I, n = 2; II, n = 6; III, n = 6; IV, n = 5 and V, n = 1. The mean MPD (J cm(-2) ) for all subjects at each wavelength was as follows: 325 nm, 0·64 (SD 0·37); 335 nm, 0·80 (SD 0·58); 345 nm, 0·96 (SD 0·55); 355 nm, 1·50 (SD 0·85); 365 nm, 2·19 (SD 0·90); and 375 nm, 2·89 (SD 1·06). Therefore, the relative sensitization at each wavelength (erythemal action spectrum) was: 1, 0·83, 0·67, 0·43, 0·29 and 0·22. There were significant differences between the PUVA erythemal effectiveness at different wavelengths but none between skin types. CONCLUSIONS: This study has established the erythemal action spectrum for bath/soak PUVA therapy as is currently performed. In all volunteers, the peak sensitivity was at 325 nm. All volunteers showed a similar trend across the wavelengths studied irrespective of skin type. The determination of the action spectrum for PUVA-induced erythema is important as it permits reliable estimates of erythemal efficacy of any UVA source where the emission spectrum of the lamp is known or can be measured.

Efficacy and safety of bexarotene combined with psoralen-ultraviolet A (PUVA) compared with PUVA treatment alone in stage IB-IIA mycosis fungoides: final results from the EORTC Cutaneous Lymphoma Task Force phase III randomized clinical trial (NCT00056056).

BACKGROUND: Psoralen plus ultraviolet A (PUVA) is the standard treatment for early stages of mycosis fungoides. There have been no adequate randomized controlled trials with sufficient power comparing this modality with other therapies. OBJECTIVE: To assess disease response and to compare the response rates of patients treated with PUVA alone or PUVA and bexarotene. METHODS: EORTC 21011 (NCT 00056056) was a randomized phase III study comparing combined bexarotene (Targretin(®) ) and PUVA vs. PUVA alone in patients with stage IB and IIA mycosis fungoides (MF). The primary endpoint was the overall response rate [complete clinical response (CCR) plus partial response (PR)]. RESULTS: The study was prematurely closed due to low accrual after 93 of 145 required patients (65%) were randomized. Of the 93 randomized patients, 87 started treatment, 41 received PUVA and 46 received PUVA + bexarotene. Total UVA doses received were 107 J cm(-2) (range 1·4-489·9) in the PUVA arm vs. 101·7 J cm(-2) (0·2-529·9) in the combination arm. The safety profile was acceptable with few grade 3-4 toxicities observed in either arm. More drop-outs due to toxicity were observed in the combination arm compared with the PUVA-alone arm. The best overall response (CCR + PR) rate was 71% for PUVA alone and 77% for the combination arm (P = 0·57). The median duration of response was 9·7 months for PUVA vs. 5·8 months for the combination arm (P = 0·33). CCR was seen in 25 patients of whom 10 received PUVA alone (CCR 22%) and 15 received combination therapy (CCR 31%) (P = 0·45). CCR was sustained in 25% of patients regardless of therapy. There was a trend towards fewer PUVA sessions needed to achieve CCR in the combination arm (median 22) compared with the PUVA arm (median 27·5) (P = 0·11). Similarly, a trend towards lower UVA dose required to achieve CCR in the combination arm (median 55·8 J cm(-2) ) compared with the PUVA arm alone (median 117·5 J cm(-2) ) (P = 0·5) was observed. CONCLUSIONS: No significant difference in response rate or response duration was observed in this study. However, there was a trend towards fewer PUVA sessions and lower UVA dose required to achieve CCR in the combination arm (PUVA + bexarotene) but this did not achieve statistical significance due to insufficient power.

Carcinogenic risks of psoralen UV-A therapy and narrowband UV-B therapy in chronic plaque psoriasis: a systematic literature review.

BACKGROUND: Oral 8-methoxypsoralen-UV-A (PUVA) and narrowband UV-B (NB-UVB or UVB TL-01) are effective and widely used treatments for chronic plaque psoriasis. Although the role of PUVA therapy in skin carcinogenesis in humans with psoriasis has been clearly demonstrated, there is still controversy regarding the risk of skin cancer with NB-UVB. Furthermore, there is no clear evidence about the maximum cumulative number of sessions not to be exceeded in a lifetime. OBJECTIVES: To assess the respective cutaneous carcinogenic risks of PUVA or NB-UVB in psoriasis; to estimate the respective dose-relationship between skin cancers and PUVA or NB-UVB; to estimate a maximum number of sessions for PUVA or NB-UVB not to be exceeded in a lifetime. METHODS: A systematic literature search was carried out in Medline, Embase and Cochrane Library databases from1980 to December 2010 in English and French, with the keywords 'Psoriasis' AND 'UVB therapy' AND 'UVA therapy' AND 'cancer' AND 'skin' OR 'neoplasm' OR 'cutaneous carcinoma' OR 'melanoma'. RESULTS: Of 243 identified references, 49 published studies were included. Most of them (45/49) concerned PUVA therapy, with 41 assessing the risk of non-melanoma skin cancers (NMSC) following PUVA. All publications referring to the US prospective PUVA follow-up study revealed an increased risk of NMSC with the following characteristics: risk most pronounced for squamous cell carcinomas developing even with low exposures and increasing linearly with the number of sessions, tumors occurring also on non-exposed skin including invasive penile tumors, risk persisting after cessation of treatment. An increased risk of basal cell carcinomas was observed in patients receiving more than hundred PUVA sessions. The four prospective European studies selected in our review and most of the pre-1990 European and US retrospective studies failed to find a link between exposure to PUVA and skin cancer. Only the most recent cohorts, including three large long-term retrospective European studies comparing records with their respective national cancer registries reported on an independent increased risk of NMSC with PUVA, The risk was lower as compared to the US prospective PUVA follow-up study. Six studies assessed the risk of melanoma following PUVA therapy: two of the three US publications coming from the same PUVA prospective follow-up study revealed an increased risk with more than doubled incidence of both invasive and in situ melanoma among patients exposed to at least 200 PUVA treatments compared with patients exposed to lower doses, whereas the three retrospectives European studies, comparing the incidence of melanoma in PUVA users with national cancer registers, did not find any increased risk of melanoma. No increased risk of skin cancer was evidenced in the four studies specifically assessing the potential carcinogenic risk of NB-UVB. CONCLUSION: There is an increased risk of skin cancer following PUVA, shown by both US and European studies. The greater risk measured by the US studies may be at least partly explained by high UVA dose exposure and the lighter phototypes of the treated patients. The lack of prospective studies in psoriasis patients treated with NB-UVB constitutes a barrier to the robust assessment of carcinogenic risk of this phototherapy technique.

Miniature swine model of phototoxicity testing.

BACKGROUND/PURPOSE: This study determined the threshold doses for 'solar erythema' and for phototoxic responses to 8-methoxypsoralen (8-MOP) in white skin Hanford and grey skin Yucatan miniature swine. METHODS: For threshold erythema determinations, the UVR exposures included both UVA (315-400 nm) and UVB (290-315 nm) radiation by positioning one fluorescent 'sunlamp' among 10 'PUVA' lamps. With this configuration the UVR exposures ranged from 0.5-2.8 times the 'instrumental MED' (MEDi) for Hanford and from 1.0-5.6 times the MEDi for Yucatan. For phototoxicity determinations (i.e., with and without topically-applied graduated concentrations of 8-MOP), the UVB component was minimized by extinguishing the sunlamp, thus permitting higher UVA exposures. RESULTS: The Hanford had the lower UV erythema dose threshold (1.0-1.4 times the MEDi) and the erythema that developed was readily observable. The exposure doses for the phototoxicity test were 5 J/cm(2) of UVA in 35 minutes or 10 J/cm(2) in 70 minutes. The phototoxic (vascular) response to 8-MOP was observed in the two highest concentrations (0.01% and 0.1%) in Hanford pigs, in a dose-related manner. Microscopic evidence of a dose-related response was also observed as the concentration of 8-MOP increased. CONCLUSION: This verified that the Hanford miniature swine is the preferable strain for phototoxic effects. In contrast, UVR exposure of the Yucatan pig skin produced tanning rather than erythema, confirming that the Yucatan is the more appropriate strain for studying the melanization response. Thus, Hanford and Yucatan miniature swine have cutaneous photobiological responses that reflect their respective strain differences.

Comparison of topical 8-methoxypsoralen and narrowband ultraviolet B with narrowband ultraviolet B alone in treatment-resistant sites in plaque-type psoriasis: a placebo-controlled study.

BACKGROUND: Combination of topical methoxsalen and narrowband ultraviolet B (NBUVB) was shown to be more effective than NBUVB alone in treating plaque-type psoriasis. OBJECTIVE: To find out whether topical methoxsalen and NBUVB had any benefit in induction of remission on treatment-resistant plaques of psoriasis on the legs in comparison with NBUVB alone. METHODS: Ten patients were included. Two symmetric lesions with similar Psoriasis Severity Index score on the lower legs were randomly assigned to be treated with cold cream as placebo or 0.1% 8-methoxypsoralen (8MOP) cream 15 min before phototherapy with NBUVB. Phototherapy was given three times per week for up to three months. Severity scores were recorded each week and side effects were observed before each session. RESULTS: Significant decrease in the severity score was observed in both groups (P-value < 0.001), but none of the lesions cleared completely at the end of the study. The decrease of the score in the 8MOP arm was greater than the control arm; however, the difference was not significant. The only side effect was pigmentation that occurred in all of the 8MOP-treated patients after 2 weeks. CONCLUSION: We could not confirm any significant benefit of topical methoxsalen and NBUVB in comparison to NBUVB alone in treating resistant plaques of psoriasis on the legs.

Leukoderma punctata following topical PUVAsol treatment.

Two adolescent females and a girl, all with clinically diagnosed vitiligo, were treated with 0.2% 8-methoxypsoralen cream followed by exposure to solar ultraviolet light. One year later, they developed hypopigmented and achromic spots on the areas affected by the vitiligo. Biopsy of skin tissue taken from one of these cases showed a marked reduction in melanin. Clinical and histological findings point to a diagnosis of leukoderma punctata.

Comparative evaluation of NBUVB phototherapy and PUVA photochemotherapy in chronic plaque psoriasis.

BACKGROUND: Psoralen UV-A (PUVA) is an established therapy for psoriasis, but there is a well-documenated risk of melanoma and nonmelanoma skin cancer. Narrow-band Ultraviolet-B (NBUVB) therapy has a lower carcinogenic risk, has equal therapeutic potential and is considerably safe in the long term than PUVA. AIM: The aim of present study was to compare the efficacy and side-effects of PUVA and NBUVB in chronic plaque psoriasis. METHODS: Sixty patients of chronic plaque psoriasis were taken up for the study and were randomly divided into two groups of 30 each. They were well matched in terms of age, sex, psoriasis extent and pretreatment psoriasis area severity index (PASI) scoring. One group was treated with twice-weekly narrow-band UV-B (TL-01) phototherapy and the other group received twice-weekly oral 8-Methoxsalen PUVA for a period of 3 months. RESULTS: Both the groups achieved >75% reduction in the PASI score or complete clearance at the end of 3 months, but PUVA group patients required significantly fewer number of treatment sessions and fewer number of days to clear the psoriasis as compared to the NBUVB group, while the mean cumulative clearance dose and adverse effects were significantly lower in the NBUVB group. CONCLUSION: We concluded that PUVA group patients achieved a faster clearance, but the adverse effects were significantly lower in the NBUVB group.

Leucodermia punctata após tratamento com Puvasol tópico / Leukoderma punctata following topical PUVAsol treatment

Duas adolescentes e uma menina com vitiligo clinicamente diagnosticado foram tratadas com 8-metoxipsoraleno a 0,2 por cento em creme Lanette com subsequente exposição solar. Um ano após, apresentaram máculas acrômicas na área do vitiligo. A biópsia de pele em um dos casos revelou melanócitos com escassa pigmentação melânica. Os achados clínicos e histológicos sugerem o diagnóstico de leucodermia punctata.

Two adolescent females and a girl, all with clinically diagnosed vitiligo, were treated with 0.2 percent 8-methoxypsoralen cream followed by exposure to solar ultraviolet light. One year later, they developed hypopigmented and achromic spots on the areas affected by the vitiligo. Biopsy of skin tissue taken from one of these cases showed a marked reduction in melanin. Clinical and histological findings point to a diagnosis of leukoderma punctata.

[Consensus document on bath-PUVA therapy. The Spanish Photobiology Group of the Spanish Academy of Dermatology and Venereology]. / Documento de consenso sobre la modalidad terapéutica del baño-PUVA. Grupo Español de Fotobiología de la Academia Española de Dermatología and Venereología.

Bath PUVA is a variant of phototherapy as efficacious as oral PUVA therapy that avoids many of the adverse effects associated to this treatment. Nevertheless, the special features and the specialized equipment required for its employment have limited its application in the dermatologic clinics of our country. Following the trend initiated after the publication of the consensus document on oral PUVA therapy and narrow band (NB) UVB therapy, the Spanish Photobiology Group from the Spanish Academy of Dermatology and Venereology has developed a therapeutic guideline for bath PUVA therapy based on the literature review and the experience of its members. The document aims to be a practical reference guide for those dermatological centres that include phototherapy among their services. It reviews the concept and indications of this type of treatment and proposes recommendations concerning therapeutic procedures, drug associations of interest and prophylaxis and management of adverse effects.

Can dietary furanocoumarin ingestion enhance the erythemal response during high-dose UVA1 therapy?

As phototoxic skin reactions caused by psoralen are induced by wavelengths within the UVA1 spectrum, we assessed the potential of the small amount of psoralen in a normal diet to provoke phototoxicity in volunteers with skin types I and II. Threshold erythema was unaffected by ingestion of a 200-g portion of parsnip.

Efficacy of 8-methoxypsoralen vs. 5-methoxypsoralen plus ultraviolet A therapy in patients with mycosis fungoides.

BACKGROUND: Psoralen plus ultraviolet (UV) A (PUVA) is the standard treatment for early stage mycosis fungoides (MF). When 8-methoxypsoralen (8-MOP) is used in PUVA therapy, it often produces intolerance reactions such as nausea, vomiting and headache. OBJECTIVES: To investigate whether 5-methoxypsoralen (5-MOP) is a safe and effective alternative to 8-MOP in PUVA therapy for MF. METHODS: A retrospective database search and chart review was done to identify patients with MF who received PUVA with either 5-MOP or 8-MOP as initial monotherapy at our institution. Between 1990 and 2004, 14 patients [seven men and seven women; mean age 70 years, range 51-82; National Cancer Institute disease stages IA (n = 6) and IB (n = 8)] received 5-MOP, and 24 patients [21 men and three women; mean age 58 years, range 28-89; disease stages IA (n = 11), IB (n = 12) and IIB (n = 1)] received 8-MOP. RESULTS: Twelve of 14 patients (86%) in the 5-MOP group and 22 of 24 (92%) in the 8-MOP group had a complete response to PUVA. These two subgroups of complete responders did not differ significantly in terms of PUVA therapy duration, number of treatments or cumulative UVA dose. They also did not differ significantly in terms of relapse-free rate [8% (one of 12) vs. 23% (five of 22)] or time to relapse [17 months (range 4-31) vs. 14 months (range 4-33)]. Moreover, PUVA maintenance therapy with either 5-MOP or 8-MOP in a subset of patients [26% (nine of 34)] did not affect long-term relapse-free status either. CONCLUSIONS: 5-MOP and 8-MOP have comparable therapeutic efficacy when used in PUVA therapy for MF.