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Radiation Safety
Published in Debbie Peet, Emma Chung, Practical Medical Physics, 2021
Debbie Peet, Elizabeth Davies, Richard Raynor, Alimul Chowdhury
As the name suggests, phototherapy ultraviolet (UV) electromagnetic wave radiation is used to treat skin conditions. Broadband UV (UVB) light uses wavelengths ranging from 280 nm to 314 nm to treat conditions such as psoriasis and eczema. Narrowband UVB uses a narrower part of the spectrum (311 nm to 312 nm), which is found to be more effective than broadband UVB for treating severe dermatological cases. PUVA therapy (psoralen + UVA) uses the UVA part of the spectrum (315 nm to 400 nm) with a photosensitising drug, called psoralen, added to treat psoriasis, vitiligo, and cutaneous T-cell lymphoma. The drug is administered as a cream to the skin or orally. Phototherapy is widely available, although audits have shown enormous variations in the quality of service and incidence of injury.
UVA Therapy in Vitiligo
Published in Vineet Relhan, Vijay Kumar Garg, Sneha Ghunawat, Khushbu Mahajan, Comprehensive Textbook on Vitiligo, 2020
Surabhi Dayal, Priyadarshini Sahu
The rationale for photochemotherapy is to maintain an adequate level of psoralen in the target organ (skin) only at the time of exposure to UV radiation. It is a unique form of therapy where the drug psoralen has no therapeutic effect by itself but produces an effect when the patient is exposed to UVA radiation. Thus, an unintentional exposure may be harmful if psoralen is present in skin before and after the exposure. The erythema induced by PUVA therapy usually appears after 36–48 hours of exposure to UVA radiation and peaks after 48–96 hours or up to 120 hours [8].
Pharmacology of Therapeutic Agents in Photomedicine
Published in Henry W. Lim, Nicholas A. Soter, Clinical Photomedicine, 2018
Ira C. Davis, Matthew J. Stiller, Jerome L. Shupack
Psoralen is the general term used to describe chemical compounds called furocoumarins, which are found in four to five major plant families. The major psoralens used in dermatology are 8-methoxypsoralen (8-MOP), 5-methoxypsoralen (5-MOP), and trimethylpsoralen (TMP) (Fig. 2).
Safety of the current drug treatments for vitiligo
Published in Expert Opinion on Drug Safety, 2020
Torello Lotti, Komal Agarwal, Indrashis Podder, Francesca Satolli, Martin Kassir, Robert A Schwartz, Uwe Wollina, Stephan Grabbe, Alexander A Navarini, Simon M Mueller, Mohamad Goldust
Psoralens, derived from the plant Psoraleacorylifolia, have been used for the treatment of vitiligo for a long time. The derivative most widely used in photochemotherapy is 8-methoxypsoralen (8MOP) which is principally of plant origin but also available as a synthetic drug. 4, 5, 8-trimethyl psoralen (TMP) is a synthetic compound, less phototoxic and is primarily used for the treatment of vitiligo [7].5-methoxypsoralen is the newest congener of this molecule under research. Acute side effects of psoralen include erythema, pruritus, nausea, headache, drug eruptions; whereas chronic side effects may be chronic phototoxicity, xerosis, hypertrichosis, hyperpigmentation, cutaneous malignancies, etc. Psoralens are absolutely contraindicated in xeroderma pigmentosum, lupus erythematosus, bullous pemphigoid, history of idiosyncratic reaction to psoralens and are relatively contraindicated in conditions like cardiac, liver, renal disease, family history of melanoma, very young children. The criteria for patient selection are age 12 or over, ability to follow the protocol, availability for 12–24 months of continuous therapy, ophthalmological examination, and vitiligo other than acro-facial variant [7]. It is a pregnancy category C drug and is excreted in breast milk.
An update on generalized pustular psoriasis
Published in Expert Review of Clinical Immunology, 2019
Melinda J. Gooderham, Abby S. Van Voorhees, Mark G. Lebwohl
Second-line therapy in adults with GPP may include combination therapy of a biologic plus nonbiologic agent. Topical treatments (e.g., corticosteroids, calcipotriene, and tacrolimus) may be useful as an adjunct to systemic therapy or as first-line therapy for mild (or localized) disease. Oral corticosteroids may be considered in GPP if other treatment choices are not possible, but these agents should be used with caution and with gradual tapering of medication, as rapid withdrawal may induce a pustular flare. Psoralen ultraviolet (UV)-A phototherapy may be considered as second-line treatment in adults (although availability may be limited) but it is not recommended for acute forms of pustular psoriasis, and is not considered to be safe during pregnancy. Granulocyte and monocyte apheresis have also been utilized successfully in some refractory cases of GPP [83,84].
The efficacy and safety of methotrexate versus interferon in cutaneous T-cell lymphomas
Published in Journal of Dermatological Treatment, 2018
Thevaki Wain, Alexandra Pavli, Jillian Wells, Pablo Fernandez-Peñas
MTX and IFN have been used in the management of CTCLs either as monotherapy or in combination with other documented therapies (3,14–16). In Australia, not all therapies reported to be effective for CTCL are available for patients. Bexarotene, a retinoid used either topically or orally, and Pralatrexate, second generation antifolate, with proven efficacy in management of CTCL are not available in Australia (17–19). To date, ECP, used in severe disease, is only available in a single center nationwide for the indication of lymphoproliferative cutaneous malignancies (20). Psoralen with ultraviolet A treatment, another staple in the management of this disease, is not accessible in most dermatology centers (21). Targeted therapies such as histone deacetylase inhibitors and alemtuzumab are not widely prescribed in most outpatient dermatology settings and often require co-management with hematologists in multidisciplinary settings (22–24). Finally, novel agents such as denileukin diftitox are only currently being prescribed in specialized research centers in Australia with vast majority of patients still unable to access these therapies (25). Thus in Australia, MTX and IFN are much more widely used in the setting of CTCL due to ease of access, low costs and ease of dosing than in other parts of the world.