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

Medical University of Graz

Status

Completed

Conditions

Polymorphic Light Eruption

Treatments

Other: Intervention: none (only UV)

Other: SPF30 sunscreen

Other: After-sun-lotion with DNA repair enzymes

Other: Placebo after-sun-lotion

Study type

Interventional

Funder types

Other

Identifiers

NCT00549588

14-058 ex 03/04

Details and patient eligibility

About

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.

Full description

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.

Enrollment

14 patients

Sex

All

Ages

19+ years old

Volunteers

No Healthy Volunteers

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