It has been suggested that polymorphic light eruption (PLE) is characterized by a failure of ultraviolet radiation (UVR)-induced immunosuppression, resulting in a type-IV hypersensitivity response to photoinduced anti...It has been suggested that polymorphic light eruption (PLE) is characterized by a failure of ultraviolet radiation (UVR)-induced immunosuppression, resulting in a type-IV hypersensitivity response to photoinduced antigens. We measured the effect of solar-simulated radiation (SSR) on the elicitation phase of contact hypersensitivity to 2,4-dinitrochlorobenzene (DNCB), in ten PLE patients and 11 controls. Subjects were given a sensitizing dose of DNCB, and 3 wk later were exposed to 0.75 and 2 minimum erythema doses (MED) of SSR on the upper inner arm. Immediately and 24 h later these sites, and a non-irradiated control site, were challenged with DNCB. The resulting increase in skin thickness was measured with high-frequency ultrasound. Overall, 2 MED caused 17%-20%suppression of elicitation responses (compared with 93%suppression of sensitization reported previously), but the effect of SSR varied greatly between subjects, with some subjects showing potentiated responses, which may be of relevance to false-positive reactions in photopatch testing. In a repeated measures general linear model, SSR overall caused significant suppression of responses (p < 0.001); there was less suppression in older subjects (p=0.009) but there was no significant difference between PLE patients and age-matched normal controls. These results contrast with our previous finding of a resistance to UVR-induced suppression of sensitization toDNCB in PLE. This difference may reflect the greater importance of Langerhans cells in the sensitization phase, and is consistent with the hypothesis that PLE arises from impaired suppression of Langerhans cell activation or migration.展开更多
Background: The severity of polymorphic light eruption (PLE)-is highly vari able. The results of studies of the prevalence, pathogenesis, provocation and tr eatment of PLE may be highly dependent on the severity of di...Background: The severity of polymorphic light eruption (PLE)-is highly vari able. The results of studies of the prevalence, pathogenesis, provocation and tr eatment of PLE may be highly dependent on the severity of disease in the patient s studied. Objectives: To produce a simple, valid and reproducible method to ass ess the severity of PLE, Patients and methods: Eighty patientswere asked about t he PLE they had experienced during the preceding 12 months, using a standardized interview comprising 16 questions. The answer to each question received a score . A PLE Severity Index (PLESI) was formulated, consisting of 10 questions, with a possible total score of 2- 100. The internal consistency of the PLESI (the ex tent to which the responses to different questions correlated with each other) w as assessed by reliability analysis, using Cronbach’s method. Twenty patients were re-interviewed 7- 27 days later to assess the repeatability of the PLESI . The ease of provocation of PLE by exposure at 24- h intervals to solar-simu lated radiation was assessed on a five-point scale in nine of the 80 subjects (the EOPSSR score). Results The value of Cronbach’s α for the PLESI was 0.77 . The distribution of the PLESI was consistent with a normal distribution, with a mean value of 52.7 and standard deviation of 19.4. It had a coefficient of rep eatability of 20.1. The PLESI was positively correlated with EOPSSR (rs = 0.69, P=0.039) and the number of years since onset of PLE (rs=0.25, P=0.03). There was no association between the PLESI and the duration of persistence of the eruptio n after ceasing sun exposure (rs=0.12, P= 0.30), the development of tolerance as summer progressed (rs=- 0.14, P=0.39), gender (P=0.50) or skin type (P=0.87). Conclusions: This study has (i) validated the concept that a single score can re flect disease severity in PLE by showing that the principal characteristics of t he condition, including, for example, the extent of anatomical distribution and the ease of provocation of the eruption, correlate with each other; (ii) formula ted the PLESI, which is a simple, valid and reproducible way of assessing diseas e severity; we suggest it could be used worldwide to determine the severity of P LE among patients enrolled in future PLE research; (iii) shown that the ease wit h which the eruption is provoked by solar-simulated radiation correlates with the severity of the condition; and (iv) shown that the duration of persistence o f the eruption after sun exposure does not correlate with the severity of the co ndition.展开更多
文摘It has been suggested that polymorphic light eruption (PLE) is characterized by a failure of ultraviolet radiation (UVR)-induced immunosuppression, resulting in a type-IV hypersensitivity response to photoinduced antigens. We measured the effect of solar-simulated radiation (SSR) on the elicitation phase of contact hypersensitivity to 2,4-dinitrochlorobenzene (DNCB), in ten PLE patients and 11 controls. Subjects were given a sensitizing dose of DNCB, and 3 wk later were exposed to 0.75 and 2 minimum erythema doses (MED) of SSR on the upper inner arm. Immediately and 24 h later these sites, and a non-irradiated control site, were challenged with DNCB. The resulting increase in skin thickness was measured with high-frequency ultrasound. Overall, 2 MED caused 17%-20%suppression of elicitation responses (compared with 93%suppression of sensitization reported previously), but the effect of SSR varied greatly between subjects, with some subjects showing potentiated responses, which may be of relevance to false-positive reactions in photopatch testing. In a repeated measures general linear model, SSR overall caused significant suppression of responses (p < 0.001); there was less suppression in older subjects (p=0.009) but there was no significant difference between PLE patients and age-matched normal controls. These results contrast with our previous finding of a resistance to UVR-induced suppression of sensitization toDNCB in PLE. This difference may reflect the greater importance of Langerhans cells in the sensitization phase, and is consistent with the hypothesis that PLE arises from impaired suppression of Langerhans cell activation or migration.
文摘Background: The severity of polymorphic light eruption (PLE)-is highly vari able. The results of studies of the prevalence, pathogenesis, provocation and tr eatment of PLE may be highly dependent on the severity of disease in the patient s studied. Objectives: To produce a simple, valid and reproducible method to ass ess the severity of PLE, Patients and methods: Eighty patientswere asked about t he PLE they had experienced during the preceding 12 months, using a standardized interview comprising 16 questions. The answer to each question received a score . A PLE Severity Index (PLESI) was formulated, consisting of 10 questions, with a possible total score of 2- 100. The internal consistency of the PLESI (the ex tent to which the responses to different questions correlated with each other) w as assessed by reliability analysis, using Cronbach’s method. Twenty patients were re-interviewed 7- 27 days later to assess the repeatability of the PLESI . The ease of provocation of PLE by exposure at 24- h intervals to solar-simu lated radiation was assessed on a five-point scale in nine of the 80 subjects (the EOPSSR score). Results The value of Cronbach’s α for the PLESI was 0.77 . The distribution of the PLESI was consistent with a normal distribution, with a mean value of 52.7 and standard deviation of 19.4. It had a coefficient of rep eatability of 20.1. The PLESI was positively correlated with EOPSSR (rs = 0.69, P=0.039) and the number of years since onset of PLE (rs=0.25, P=0.03). There was no association between the PLESI and the duration of persistence of the eruptio n after ceasing sun exposure (rs=0.12, P= 0.30), the development of tolerance as summer progressed (rs=- 0.14, P=0.39), gender (P=0.50) or skin type (P=0.87). Conclusions: This study has (i) validated the concept that a single score can re flect disease severity in PLE by showing that the principal characteristics of t he condition, including, for example, the extent of anatomical distribution and the ease of provocation of the eruption, correlate with each other; (ii) formula ted the PLESI, which is a simple, valid and reproducible way of assessing diseas e severity; we suggest it could be used worldwide to determine the severity of P LE among patients enrolled in future PLE research; (iii) shown that the ease wit h which the eruption is provoked by solar-simulated radiation correlates with the severity of the condition; and (iv) shown that the duration of persistence o f the eruption after sun exposure does not correlate with the severity of the co ndition.
