Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0349506 (photosensitivity)
 4,145 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The therapeutic spectrum for ultraviolet radiation treatment of skin disease has continued to be broadened. Psoralen photochemotherapy is beneficial in chronic lichenoid graft-versus-host disease and disseminated granuloma annulare. This treatment is now being found more useful in atopic eczema and chronic photosensitivity with some modifications of the therapy. UV phototherapy has also been found useful in mild to moderate atopic eczema. The nature of these treatments is also changing with greater use of selective UV phototherapy and definition of the required schedule for maintenance treatment with UVB phototherapy. The mechanism of therapeutic benefit remains unknown although one possibility is selective phototoxicity for inflammatory cells in the dermis. Nonmelanoma skin cancer, premature aging of the skin and freckling are the main long-term adverse effects of these treatments.
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PMID:Recent advances in phototherapy and photochemotherapy of skin disease. 208 2

Psoralen photochemotherapy (PUVA) is a combination of orally administered psoralen and long wave ultraviolet-A radiation (UVA), and is one of the most effective forms of therapy for psoriasis. The unwanted effects of PUVA therapy can be divided into short and long term adverse effects. The short term adverse effects include erythema, pruritus, nausea and headache. While short term adverse effects are limited and reversible after discontinuation of treatment, potential long term adverse effects such as chronic actinic skin damage, dyskeratotic and precancerous skin conditions, nonmelanoma skin cancer, immunological alterations and cataract formation are of greater concern. Long term risks associated with PUVA therapy can be minimised by several measures. Careful patient selection is mandatory; for example, patients with chronic actinic damage and a history of skin cancer may bear a higher risk for the development of new cancers, and previous arsenic intake and ionising radiation also increase the risk of nonmelanoma skin cancers. Certain drug combinations make it possible to lower the UVA dose, which is important because of the dose-dependent increase in the incidence of squamous cell carcinomas in patients treated with PUVA. It has been demonstrated that 200 treatments or a total UVA dose of 1200 J/cm2 seems to be the threshold for development of nonmelanoma skin cancer. Shielding male genitalia during PUVA treatment is essential because of the increased risk of genital squamous cell carcinomas. Yearly dermatological examination to detect skin cancer at an early stage is highly advisable. Sunscreen use, protective clothing and avoidance of sun exposure reduce the uncontrolled dose of solar UV radiation. Other psoralens with a less carcinogenic potential can be used. UVA-opaque sunglasses during the entire period of increased photosensitivity after psoralen ingestion help avoid cataract formation. Assignment to PUVA ought to be based on the risk-benefit ratio for the individual patient and should be limited to those who can be monitored and controlled by informed, competent and conscientious physicians.
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PMID:Minimising the risks of PUVA treatment. 850 16

Shower PUVA is a new variant of photochemotherapy suitable for therapy of various skin disorders. Psoralen, e.g. trioxsalen-containing water recirculates in a closed shower system and wets the skin continuously. After showering, whole-body UVA irradiation (320-400 nm) is performed. In order to prove the equal distribution of photosensitivity in vivo minimal phototoxic dose (MPD) was determined in different skin areas of healthy individuals. Additionally, we investigated the accumulation of trioxsalen in psoriasis lesions under the conditions described by quantifying psoralen in scales collected after showering. In a randomized study 20 healthy volunteers (skin type I-III) took showers for 5 and 10 min in trioxsalen (0.27 mg/l)-containing water at 37 degrees C. Immediately afterwards, MPD was tested on the inside of the upper arms and on the buttocks by using a polychromator light source (315-400 nm). The applied UVA doses were 0.06-0.75 J/cm(2) with steps of 0.125 J/cm(2). MPD was evaluated after 72 h. Equal distribution of photosensitivity was defined as equal MPD on the insides of the upper arm and the buttocks (+/-0.125 J/cm(2)). Skin scales of 21 patients with psoriasis were collected by scratching after showering with trioxsalen-containing water (0.27 mg/l) for 5 min. For quantification of trioxsalen in the scales HPLC was performed. An equal distribution of photosensitivity was achieved in 70% (14/20) cases after 10-min showering in trioxsalen-containing water. Showering for 5 min only revealed a 30% (6/20) rate of equal distributed photosensitivity. After 10-min shower time MPD was 0.325 J/cm(2) (median; range: 0.06-0.625 J/cm(2)). The average amount of trioxsalen found in the scales was 2.03 ng/mg scales (range: 0.38-7.2 ng/mg). For shower PUVA using trioxsalen, 10 min shower time is recommended to achieve sufficient distribution of photosensitivity on the skin. Clinical efficacy of shower PUVA can be explained by skin accumulation of trioxsalen which enters from the aqueous phase into the upper skin layers in detectable amounts. This is the first report demonstrating the efficacy of shower PUVA which in short shower time allows an uptake of psoralen by the skin.
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PMID:Shower PUVA: a novel variant of photochemotherapy. Distribution of photosensitivity and accumulation of trioxsalen in the skin. 1508 92