Mainz University Medical Center investigates new treatment option and its mechanism of action
05.09.2011
Photodynamic or blue light therapy may well be an effective treatment option for patients suffering from neurodermatitis. This has been demonstrated by a study involving 36 patients at the Department of Dermatology at the Mainz University Medical Center. Additional studies with larger groups of participants will now be necessary to confirm this result and to learn more about the actual mechanism of action of photodynamic therapy.
In industrialized countries, 10 to 15 percent of the population suffers from neurodermatitis of differing degrees of severity. It is a condition which often develops during the first years of life. Dry, flaking, inflamed skin and sometimes bothersome itching are the main symptoms of the disorder. No curative treatment has been developed to date, although it is possible to manage symptoms depending on form and degree of severity using various methods. These methods include treatment with immunosuppressants and exposure to UV radiation. Daily basic skin care with moisturizing creams and lotions is particularly important.
Because UV radiation can be carcinogenic, long-term exposure is not generally to be recommended. It is thus essential to develop and test methods that do not involve the use of UV radiation, such as the blue light therapy. This form of photodynamic therapy was initially used for the treatment of hand and foot eczema and resulted in significant alleviation of the clinical symptoms. It was also observed that this treatment helped in the long-term management of the conditions, even in severe cases. In the recent study undertaken at the Department of Dermatology at the Mainz University Medical Center, the investigators were interested in discovering to what extent photodynamic therapy can influence the clinical progress of the disorder in patients with severe neurodermatitis and the details of how the therapy actually works. The study subjects underwent full-body radiation for several months in accordance with a detailed protocol. After each radiation session, the clinical symptoms were assessed, characteristic lab parameters determined, and the patients were asked various questions, such as to what extent they experienced itching. "The results of observation of the clinical symptoms and the assessments of patients showed that full-body radiation with blue light is a viable way of controlling the disorder over the long-term," explained PD Dr. Detlef Becker, senior physician at the Dermatology of Dermatology and primary author of the study. "Overall, following a six-month course of treatment, there was significant alleviation of symptoms, which we assessed on the basis of the EASI score, the standard tool used to determine the extent and severity of neurodermatitis."
The analyses of skin biopsy samples and the results of lab tests revealed that photodynamic therapy had no significant immunosuppressant effects on the dermal inflammation process. Hence the effect does not appear to be attributable to the short-term suppression of inflammation. This may represent the decisive difference to the known standard treatments for neurodermatitis, which result in a significant but unfortunately often only temporary reduction of inflammation. The results observed during photodynamic therapy seem to indicate this is associated with a long-term effect in terms of the deregulation of inflammation.
"Now that we have obtained these promising initial results, we need to continue to investigate the effects of photodynamic therapy in comparison with effects in a control group, and in particular we need to find out what the mechanism of action is," added Becker. "This is why we will be initiating a clinical study in which adult patients between the ages of 18 and 40 who have suffered from moderate to severe neurodermatitis for several years will be able to participate." During the study, when patients suffer an acute episode of eczema, they will be subjected to a block of five radiation sessions on successive days. A second group of subjects will undergo control radiation sessions. It will of course not be possible for the study participants to differentiate between these and the actual blue light treatment sessions. This will provide for blinding identical to that used during clinical trials of new medicaments. "We want to examine the efficacy of photodynamic therapy at a particularly high clinical level. This might result in the establishment of the procedure as one of the range of recognized treatment methods and as a viable option for the long-term management of neurodermatitis," Becker summarized the objectives of the planned study.