Photoaggravated Dermatoses
Henry W. Lim, Herbert Hönigsmann, John L. M. Hawk in Photodermatology, 2007
Patients with psoriasis usually benefit from sunlight and UV phototherapy. However, some patients experience exacerbation of their disease after sun bathing, particularly, after sunburn (40–42) (Fig. 5). The exact incidence of this photosensitive form of psoriasis is not known and varies in the literature from 5.5% to 24%. In a questionnaire study encompassing 2000 patients in Sweden, the prevalence of photosensitivity was 5.5% (42). Forty-three percent of the light-sensitive patients had a history of polymorphous light eruption with secondary exacerbation of psoriasis lesions. Comparison between the photosensitive and the nonphotosensitive patients showed a statistically significant increase in type I skin, psoriasis affecting hands, heredity for photosensitivity, and advanced age in the photosensitive group. The investigators proposed that many patients developed polymorphous light eruption and secondarily psoriasis as a Koebner phenomenon (42). Interestingly, despite photosensitivity, in our experience and in that of others such patients can be successfully treated with photochemotherapy (43). In summary, photosensitivity is well recognized but poorly defined in psoriasis. Many patients probably have polymorphous light eruption, other light sensitivity (44,45), or fair skin to explain the subsequent development of psoriatic lesions as a Koebner phenomenon.
Lukoskin
Parimelazhagan Thangaraj in Medicinal Plants, 2018
Steroids may be helpful in repigmenting the skin (returning the colour on white patches), particularly if started early in the disease. Corticosteroids are a group of drugs similar to the hormones produced by the adrenal glands (such as cortisone). Doctors often prescribe a mild topical corticosteroid cream for children under 10 years old and a stronger one for adults (Nagai et al. 2000). Patients must apply the cream to the white patches on their skin for at least three months before seeing any results. It is the simplest and safest treatment, but not as effective as psoralen photochemotherapy. There are different levels of potency of corticosteroids in use, ranging from low potency drugs, such as desonide (0.5% dexamethasone; 1% hydrocortisone; 0.25%, 0.5%, 1% & 2.5% methylprednisolone; 0.5% & 1% prednisoline) medium potency drugs like betamethasone valerate (1% sillorasone diacetate; 0.05%, fluocinol acetoxide; 0.1%, 0.25% & 1% triaminocinlone actinide) to high-potency corticosteroid like betamethasone dipropionate (0.05% cholesterol; 0.05% propionate; 0.05% fluocinonide and 0.1% halcinonide). The topical steroid therapy is useful only at the initial stage and resticated to localized lesions on the face and eyelids, mostly in children.
Photodynamic Therapy
Henry W. Lim, Nicholas A. Soter in Clinical Photomedicine, 2018
Photochemotherapy can be used for lesions accessible to light that is transmitted through the body surface or directed internally, via an optical fiber. Fibers may be inserted within tumors, permitting treatment of large masses. Thus, cutaneous, endobronchial, intra-abdominal, bladder, and central nervous system malignancies are amenable to this technique. The prototype, first-generation photosensitizer is hematoporphyrin derivative and the partially purified fraction of hematoporphyrin derivative called Photofrin II. Because hematoporphyrin derivative/Photofrin II produces singlet oxygen upon illumination (1), treatment with these compounds is appropriately called photodynamic therapy. The tumor-localizing properties of hematoporphyrin derivative were first described by Lipson (2), and subsequently by Dougherty (3). Photodynamic therapy with hematoporphyrin derivative or Photofrin II has been used on a variety of tumor types with significant clinical benefit (4–22, 35). Since 1977 about 5,000 patients have been treated with hematoporphyrin derivative or Photofrin II. Results are very encouraging with palliation of advanced tumors and cures of early disease. Phase III trials for bladder, lung, and esophageal cancers are currently underway. At our institution we have had excellent results in the treatment of several different types of cutaneous lesions including basal- and squamous-cell carcinomas (4, 14, 22, 35), recurrent or metastatic breast cancer (10), Kaposi’s sarcoma, and cutaneous T-cell lymphoma.
Susceptibility of oral bacteria to antibacterial photodynamic therapy
Published in Journal of Oral Microbiology, 2019
Si-Mook Kang, Hoi-In Jung, Baek-Il Kim
In the early 1900s, von Tappeiner and his colleague Oscar Raab discovered that a substance called Acridine could kill paramecia upon light irradiation, and in combination with oxygen they introduced the term ‘photodynamic action’ for this phenomenon [5]. Photodynamic therapy (PDT) using a photosensitizer (PS) and light is easy to implement and apply in many fields. In particular, antibacterial PDT (aPDT) has many advantages as a new alternative to antibiotics because it does not induce the tolerance in bacteria that has become a major problem in recent years [6–8]. PDT has also been shown to be highly effective in the field of dentistry [9]. The antibacterial effects of PDT on bacteria associated with peri-implantitis, periodontitis, and caries pathogens have also been reported [10–12]. However, most of these studies used excitation light with a wavelength longer than 500 nm. A longer wavelength will increase the penetration depth but decrease the light energy, hence reducing the clinical antimicrobial effects. In addition, few studies have investigated the sensitivity of bacteria to different types of PS. The purpose of the present study was to determine the sensitivity of four PSs to violet-blue light in six representative oral bacteria species that cause intraoral diseases.
Self-assembled thermal gold nanorod-loaded thermosensitive liposome-encapsulated ganoderic acid for antibacterial and cancer photochemotherapy
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Weiwei Zhang, Wenwen Yu, Xiaoyuan Ding, Chenyang Yin, Jing Yan, Endong Yang, Feng Guo, Dongdong Sun, Weiyun Wang
The potential in vivo toxicity is usually a significant concern for the clinical application of photochemotherapy drugs. To evaluate the toxicity of the Au-LTSL-GA.A + NIR irradiation treatment, blood biochemical and immunohistochemistry assays were performed to examine possible in vivo toxicity in mice after treatment. As shown in Figure 10(A), the levels of cholesterol, blood glucose, uric acid, and alanine aminotransferase in the NIR irradiation and Au-LTSL-GA.A + NIR irradiation groups were similar to those found in the blank group. They all showed healthy blood biochemical indicators. This result was also confirmed by H&E staining of major organs. The blank, NIR irradiation and Au-LTSL-GA.A + NIR treatment groups showed similar histological features, with no obvious impairment or inflammation (Figure 10(B)). These results indicated the safety of the use of the Au-LTSL-GA.A + NIR treatment in mice.
Evaluating crisaborole as a treatment option for atopic dermatitis
Published in Expert Opinion on Pharmacotherapy, 2019
Vignesh Ramachandran, Abigail Cline, Steven R. Feldman, Lindsay C. Strowd
Treatment of AD involves nonpharmacologic interventions, topical medications, phototherapy, and systemic drugs including biologic agents. Topical pharmacotherapy with corticosteroids, which downregulate immune response, are first-line [6,14]. Topical tacrolimus and pimecrolimus inhibit calcineurin-dependent T cell activation preventing cytokine production. It is especially used in steroid-refractory disease, steroid-induced atrophy, steroid-free maintenance treatment, and areas of thin skin [6,15]. Phototherapy and photochemotherapy, which work via multiple mechanisms including immune and cytokine suppression, serve an alternative modality when disease is refractory to topical treatments [16–20]. Systemic therapies are used in severe disease, and include azathioprine, cyclosporine, methotrexate, and mycophenolate mofetil [6]. Biologic agents are also now available for the treatment of AD [21].
Related Knowledge Centers
- Acne
- Herpes
- Oxygen
- Reactive Oxygen Species
- Cancer
- Psoriasis
- Malignancy
- Light Therapy
- Phototoxicity
- Photosensitizer