Sunscreen and After-sun-lotion Protection in Polymorphic Light Eruption

Study Overview
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Brief Summary
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Polymorphic light eruption (PLE) is a common photodermatosis characterized by the appearance of itching, erythema, papules or vesicles on sun-exposed skin. Though etiology is unclear it is hypothesized that it is an abnormal immune response to autologous antigens generated by ultraviolet radiation (UVR). This randomized, double blinded left-right body side experimental comparison study was designed to assess the preventive effect of a sunscreen and topical DNA repair enzyme-containing after-sun lotion in PLE.

Detailed Description
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A SPF 30 sunscreen (containing chemical and physical UV filters), an after-sun lotion containing liposomal encapsulated micrococcus luteus lysate with endonuclease activity and photolyase (active AS), and an after-sun placebo formulation (containing no DNA repair enzymes) (placebo AS) has been used in this study. Fourteen PLE patients were enrolled. On day 1, the individual minimal erythema dose (MED) was assessed on patients' buttock skin by exposure to a test ladder of solar-simulated UVR (xenon arc source, Oriel Corp. Darmstadt, Germany). From day 2 to 5, 0.75 individual MED exposures (increased by 0 to 25% per exposure, depending on the erythema response to a preceding dose) were given to a total of four 5-by-5 cm skin test fields on symmetrically located, individual PLE predilection sites on the trunk or extremities. The test fields were treated in randomized and double-blinded fashion either with SPF30 sunscreen 20 min before UVR exposure, active AS or placebo AS (all creams at a concentration of 2mg/cm2) immediately after UVR exposure, or left untreated. Sixty minutes after UVR exposure all test areas were treated with visible light (400 to 450nm, 5J/cm2) to activate the light dependent photolyase DNA repair mechanism. The photo test procedure led to the appearance of PLE symptoms in unprotected test fields of 12/14 (86%) patients, active AS-treated test fields of 6/14 (43%) patients (p<0.05), placebo AS-treated test fields of 10/14 (71%) patients (p, ns), and no (0%) sunscreen-protected test fields of any patient (p<0.0001 vs. unprotected test fields, Fisher exact test). These results provide evidence that i) DNA damage is a trigger of PLE, ii) increasing DNA repair can prevent induction of PLE symptoms, and iii) the use of sun care preparations containing DNA repair enzymes may be clinically useful for PLE patients.

Official Title
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The Efficacy of a Sunscreen With SPF30 and a After-sun-lotion in the Prevention of Polymorphic Light Eruption

Conditions
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Polymorphic Light Eruption

Intervention / Treatment
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* Other: After-sun-lotion with DNA repair enzymes
* Other: SPF30 sunscreen
* Other: Placebo after-sun-lotion
* Other: Intervention: none (only UV)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of PLE either by typical history and/or typical histology of lesions and/or positive phototesting results Exclusion Criteria: Presence of or history of malignant skin tumors Dysplastic melanocytic nevus syndrome Photosensitive diseases such as porphyria, chronic actinic dermatitis, Xeroderma pigmentosum, basal cell nevus syndrome, and others Autoimmune disorders such as Lupus erythematosus or Dermatomyositis Psychiatric disorders Systemic treatment with steroids and/or other immunosuppressive drugs Pregnancy or lactation Antinuclear antibodies UV exposure in test fields within 8 weeks before study start General poor health status

Ages Eligible for Study
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Minimum Age: 19 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: After-sun-lotion with DNA repair enzymes|2 mg/cm2 immediately after UV exposure|
|Other: SPF30 sunscreen|2 mg/cm2 2o min before UV exposure|
|Other: Placebo after-sun-lotion|2mg/cm2 immediately after UV exposure|
|Other: Intervention: none (only UV)|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Occurrence of symptoms of polymorphic light eruption |  | Prospective | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pruritus |  | Prospective | 
| Skin infiltration |  | prospective | 
| Area affected |  | prospective | 
| Erythema |  | prospective | 
| Tanning |  | Prospective | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Polymorphic light eruption, UV radiation, photoprotection, sunscreen, DNA repair enzymes, after-sun-lotion