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Background/purpose: Atopic dermatitis (AD) is a common and extremely burdensome skin disorder with limited therapeutic options. Ultraviolet (UV) phototherapy is a well tolerated, efficacious treatment for AD, but its use is limited by a lack of guidelines in the optimal choice of modality and dosing. Given this deficit, we aim to develop suggestions for the treatment of AD with phototherapy by systematically reviewing the current medical literature.
Methods: Data sources: All data sources were identified through searches of MEDLINE via the Ovid interface, the Cochrane Central Register of Controlled Trials, and a complementary manual literature search.
Study selection: Studies selected for review met these inclusion criteria, as applied by multiple reviewers: controlled clinical trials of UV phototherapy in the management of AD in human subjects as reported in the English-language literature. Studies limited to hand dermatitis and studies in which subjects were allowed unmonitored use of topical corticosteroids or immunomodulators were excluded.
Data extraction: Included studies were assessed by multiple independent observers who extracted and compiled the following data: number of patients, duration of treatment, cumulative doses of UV radiation, adverse effects, and study results. Data quality was assessed by comparing data sets and rechecking source materials if a discrepancy occurred.
Results: Nine trials that met the inclusion criteria were identified. Three studies demonstrated that UVA1 is both faster and more efficacious than combined UVAB for treating acute AD. Two trials disclosed the advantages of medium dose (50 J/cm2) UVA1 for treating acute AD. Two trials revealed the superiority of combined UVAB in the management of chronic AD. Two additional studies demonstrated that narrow-band UVB is more effective than either broad-band UVA or UVA1 for managing chronic AD.
Conclusion: On the basis of available evidence, the following suggestions can be made: phototherapy with medium-dose (50 J/cm2) UVA1, if available, should be used to control acute flares of AD while UVB modalities, specifically narrow-band UVB, should be used for the management of chronic AD.
Atopic dermatitis (AD) is a common chronic skin disease characterized by severe pruritus. It usually appears in infancy or childhood and may persist into adulthood. First introduced in the 1950s, topical corticosteroids have long been the standard of care for the treatment of AD (1). However, their long term use is limited by the prevalence of adverse effects, including epidermal atrophy, telangiectasias, striae, and systemic absorption leading to suppression of the hypothalamic–pituitary–adrenal axis. These limitations create the need for ‘steroid sparing’ alternative treatments. Non-steroidal therapies of AD include emollients, topical calcineurin inhibitors, antihistamines, and cyclosporine. These treatments again are limited by lack of efficacy and side effects. Treatment with ultraviolet (UV) phototherapy has been successfully used in the management of this disease and may represent one of the most efficacious, well-tolerated treatments of AD.
In 1978, Morison et al. (2) published one of the earliest reports of UV phototherapy for AD. This study, prompted by the clinical observation that many atopic patients demonstrate appreciable improvement during the summer months, documented the benefits of psoralen photochemotherapy with UVA for patients with AD. This seminal study was followed by many reports on UV phototherapy for AD, but relatively few randomized controlled clinical trials have been undertaken. Furthermore, there are no evidence-based, standardized therapeutic guidelines for UV phototherapy of AD, making decisions about the optimal therapy to choose, dosing, and the need for maintenance difficult for the clinician. This problem is compounded by the fact that trials actually providing this level of data are unlikely to be undertaken anytime soon.
In an attempt to address this deficiency, we aim to establish recommendations for UV phototherapy of AD by systematically reviewing the current medical literature on the subject.
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AD is a burdensome, chronic disorder with frequently inadequate therapeutic options. Phototherapy may represent a safe, efficacious option in the treatment of these patients, but there is no evidence-based, standardized protocol, impairing clinical decision making in the choice of optimum therapies for individual patients. In an attempt to address this deficit, we conducted a systematic review of the currently published literature in order to create evidence-based treatment suggestions for UV phototherapy of AD.
The conclusions that may be drawn by systematically analyzing the current medical literature regarding phototherapy and AD are limited by several factors. First, as with any systematic review, publication bias must be considered. Trials yielding positive results are more likely to be published (14). Also, the small sample sizes of most of the trials make for poor statistical power and rarely disclose any uncommon adverse effects (14). The variability of the parameters used in different trials must be taken into consideration. Different methods for patient selection, administering and dosing UV radiation, and assessing the clinical response restrict our ability to draw detailed conclusions through a comprehensive review of available studies. Another limitation is the lack of trials meeting our inclusion criteria that examine combination therapy or maintenance therapy. Furthermore, these studies did not include children, hence we are unable to draw conclusions for paediatric AD patients. As a result, we are only able to make general recommendations about which phototherapy modality is appropriate for certain adult patients depending on clinical stage of disease and dosing recommendations for UVA1 therapy.
First, phototherapy with UVA1 is probably the most efficacious modality for treating acute AD, when it is available. Because medium-dose therapy (50 J/cm2) is as effective as high-dose therapy (130 J/cm2) with less cumulative radiation exposure, medium-dose constitutes the optimal fluence for UVA1 phototherapy of acute AD. In addition, the maximal clinical response usually occurs within 2 weeks (or about 10 treatments) of beginning UVA1 phototherapy. Therapeutic response to UVA1 should not be expected to persist beyond 2 or 3 months. Therefore, UVA1 may be ideal for flaring AD patients in which rapid control is desired. The short-lived duration of response indicates that a plan for maintenance treatment with topical steroids, NBUVB, or with other modalities should be in place at the time UVA1 is discontinued. At this time, no recommendations can be made for the optimal maintenance regimen after UVA1 phototherapy for AD.
Phototherapy with UVB modalities, particularly NBUVB, should be used to manage chronic AD. In the absence of data specifying the most favourable dosing protocols, we anticipate that clinicians will extrapolate from guidelines for managing psoriasis when treating chronic AD with UVB phototherapy. In addition, these recommendations are limited by the fact that AD cannot usually be separated into acute and chronic phases, and no guidelines exist for this classification scheme. Furthermore, at this time the availability of UVA1 light sources is relatively limited. The most definitive conclusion is that phototherapy (any wavelength) is a valid therapeutic option for AD. This arrangement is suboptimal and highlights the need for further investigation.
To allow for cross-comparison and comprehensive review, standardized trial protocols should be instituted. If future studies employ standardized dosing regimens, cumulative exposures, UV wavelengths, and patient evaluation methods, we anticipate that comprehensive therapeutic guidelines could be established by systematically considering all study results.