Management of polymorphous light eruption : clinical course, pathogenesis, diagnosis and intervention.

Optimal management of patients with polymorphous light eruption (PLE), the most frequent photodermatosis, requires knowledge of the individual clinical course of the disease and pathogenic factors. As PLE often causes problems during leisure-time activities and holidays, resulting in a substantial loss of quality of life, prophylaxis is the most important therapeutic approach. Management of PLE must, therefore, focus on basic preventative measures and additional therapeutic approaches, depending on the clinical condition. PLE can be classified into four severity groups (mild, moderate-to-severe, severe and therapy-resistant), which are useful for determining appropriate prophylactic measurements. No specific laboratory tests are available for the diagnosis of PLE, therefore, a clinician must rely on the clinical appearance of the disorder (e.g. clinical symptoms, the location of the lesions, the relationship of the occurrence of the lesions with sun exposure and the time course of the lesions) as well as a patient's medical history in order to make a diagnosis. Basic preventative management of PLE consists of adequate sun protection comprising avoidance of sun exposure, the use of textile sun protection and the application of broadband sunscreens with high UVA protection potential. Other supportive measurements have to be managed individually and are dependent on the patient's medical history and the severity of the disease. Topical antioxidants, systemic immunomodulation, photo(chemo)therapy and systemic immunosuppression may be required in some cases of PLE. Topical antioxidants represent a new treatment approach for moderate-to-severe PLE and are an effective and well tolerated option for this patient population. Severe PLE also requires photo(chemo)therapy. Phototherapy can be in the form of 311 nm UVB or UVA1 irradiation. In cases where 311 nm UVB or UVA1 are ineffective, psoralen plus UVA (PUVA) bath therapy may be used. However, PUVA bath therapy must be used with caution because it is associated with acute and long-term adverse effects. In rare exceptions we would consider using oral PUVA therapy. However, in our outpatient department, quality of life of most patients is improved with the treatment regimens that are recommended for patients with moderate-to-severe PLE, without the need for photo(chemo)therapy.