Blocking or enhancing effects of some basic emollients in UVA penetration

Investigation 238 s Blocking or enhancing effects of some basic emollients in UVA penetration* Sevgi Akarsu1 Ozlem Ozbagcivan1 Emel Fetil1 Ali Tahsin Gunes1 DOI: http://dx.doi.org/10.1590/abd1806-4841.20186869 Abstract: Background: Topical agents used in combination with phototherapy or photochemotherapy may have both blocking or enhancing effects in ultraviolet rays. Objective: In this in vivo study, the effects of topical petrolatum, basis cream, glycerine, and olive oil on the transmission of ultraviolet A radiation were investigated. Methods: A test was performed to determine the minimal phototoxic dose on 29 volunteers with only psoralen plus ultraviolet A (PUVA) and then the same test was repeated with white petrolatum, basis cream, glycerine, olive oil, and sunscreen (0.3cc/25cm2). The effects of each agent on the minimal phototoxic dose were determined after 72 h. Results: When compared to pure PUVA, there was a statistically significant increase in the mean minimal phototoxic dose values by the application of white petrolatum (P = 0.011), but there was no significant increase or decrease in the mean minimal phototoxic dose values after the application of basis cream (P = 0.326), glycerine (P = 0.611) or olive oil (P = 0.799). Study limitations: Low number of patients Conclusion: The application of white petrolatum, which has a blocking effect, and also of basis cream immediately before PUVA therapy should not be recommended. Although we specify that glycerine and maybe olive oil can be used before photochemotherapy, there is a need for further research in larger series. Keywords: Petrolatum; PUVA therapy; Skin cream; Ultraviolet rays INTRODUCTION Various topical agents may be used with ultraviolet B (UVB) and psoralen plus ultraviolet A (PUVA) therapy. Even though emollients are usually the constituents of the phototherapeutic regimen and they are frequently used as skin-care products to prevent the drying effect of UVB radiation, we still have no certain evidence for selecting the optimal emollient to be used in combination with PUVA photochemotherapy. However, the adequate penetration of UVA radiation into the deeper portions of skin is very important to achieve an effective treatment while using emollients with PUVA regimens.1-7 Certain emollients seem to have significant photoprotective properties by diminishing the UV penetration; however, the transmission of radiation has been found to be increased following the application of some particular lipophilic compounds. 1-10 So, according to their effects, topical administration of emollients immediately before PUVA therapy can be recommended if they are known to enhance UVA transmission, or can be avoided if they are known to block UVA transmission. Therefore, we should know about the blocking or enhancing effects of the frequently used emollients on the UVA penetration. In this in vivo study, we examined the effects of some basic emollients (petrolatum, basis cream, glycerine, olive oil) on the transmission of UVA. METHODS The study was designed as a single-blind, vehicle-controlled study to determine the minimal phototoxic dose (MPD) after the application of white petrolatum, basis cream, glycerine, and olive oil. The test was carried out on 29 volunteers with the diagnosis of psoriasis, lichen planus, parapsoriasis, mycosis fungoides, and vitiligo before their PUVA therapy. Eleven patients had skin type II, 15 patients had skin type III, and three patients had skin type IV. Received on 02.01.2017. Approved by the Advisory Board and accepted for publication on 14.02.2017. * Work was performed at the Department of Dermatology, Faculty of Medicine - Dokuz Eylul University Izmir, Turkey. Financial support: None. Conflict of interest: None 1 Department of Dermatology, Faculty of Medicine, Dokuz Eylul University – Izmir, Turkey. Mailing address: Ozlem Ozbagcivan E-mail: ©2018 by Anais Brasileiros de Dermatologia An Bras Dermatol. 2018;93(2):238-41. Blocking or enhancing effects of some basic emollients in UVA penetration 239 The study was approved by an ethics committee. All participants were informed and their consent forms were obtained. The patients were untanned and not taking any medication. Waldmann 8001 K (Waldmann Lichttechnik GmbH, Schwenningen, Germany) cabinet was used for the light source of UVA. The MPD test was performed on the volunteers 2 hours after taking 0.6-0.8 mg/kg 8-methoxypsoralen. According to the skin types of the volunteers, the doses of UVA were determined. Patients with skin types I and II were exposed to the doses of 0.5-5 J/cm2 and patients with skin types III and IV were exposed to the doses of 1.59 J/cm2 of UVA. [7] The MPD values were determined by irradiating the 4 cm2 of uninvolved skin on the back of each patient in eight different areas, in one row, with the increments of 1 J/cm2 (0.5 J/ cm2 only for the first one). In addition, 5 parallel rows of skin were tested after the application of different topical agents. The first row was only irradiated by UVA without applying any topical agent to determine the MPD. Then white petrolatum, basis cream, glycerine, MPD values detected after the application of basis cream, glycerine, and olive oil did not show statistically significant difference compared with pure PUVA, the mean MPD value detected after the application of white petrolatum showed a statistically significant difference. These findings showed that the MPD values were significantly increased by the application of white petrolatum, but there was no significant increase or decrease in the MPD values after the application of basis cream, glycerine or olive oil. The MPD values detected after the application of white petrolatum were compared, one by one, with the MPD values detected after the application of basis cream, olive oil, glycerine and each comparison was found statistically significant. Additionally, the MPD values detected after the application of basis cream were compared with the MPD values detected after the application of glycerine and a statistically significant difference was found. However, there was no statistically significant difference between the MPD values after the application of olive oil when compared with basis olive oil, and a sunscreen factor 30 (titanium dioxide+triethanolamine) were applied in a layer (0.3 cc/25 cm2) respectively to the adjacent parallel rows and irradiated with UVA, immediately after the application of the agents. The results were evaluated after 72 hours by a blinded investigator and the MPD values were determined for each row (Figure 1). Wilcoxon signed ranks test and paired t-tests were used to compare the results obtained after the application of different emollients with each other and pure PUVA. p<0.05 was considered as statistically significant. cream and glycerine. The results of the Wilcoxon signed ranks test of all paired groups are shown in table 2. RESULTS The results of the MPD tests of the pat (...truncated)