Dermatitis de contacto fotoalérgica y test de fotoparches: revisión de la literatura y aplicación de la técnica en clínica alemana de Santiago / Photoallergic contact dermatitis and test photopatches: literature review and application of the technique at clínica alemana de Santiago

Las fotodermatosis son un conjunto de patologías cutáneas originadas o agravadas por exposición a radiación ya sea solar o artificial. Se clasifican en cuatro categorías: 1. Idiopáticas o mediadas inmunológicamente 2. Dermatosis fotoagravadas, 3. Fotosensibilidad inducida por agentes y 4. Trastornos por reparación defectuosa del ADN. La fotosensibilidad inducida por agentes consiste en reacciones secundarias a la exposición de ciertos químicos, llamados fotosensibilizadores y a distintos tipos de radiación lumínica. Los fotosensibilizadores pueden ser de origen endógeno o exógeno, aquellos exógenos provienen desde el ambiente, fármacos u otros productos (tanto sistémicos como tópicos), los cuales sufren modificaciones estructurales al entrar en contacto con radiación, provocando como consecuencia, distintas manifestaciones cutáneas. En este artículo se revisarán principalmente las reacciones fototóxicas y fotoalérgicas (ambas, reacciones de fotosensibilidad inducidas por agentes exógenos) indagando en sus diferencias y el enfrentamiento clínico de cada una. También, se revisarán los exámenes que permiten estudiar los distintos diagnósticos diferenciales, especialmente el test de fotoparches, el cual está cobrando cada vez más importancia en la práctica clínica.

Photodermatoses are a group of skin diseases induced or aggravated by exposure to radiation, whether solar or artificial. They are classified into four general categories: 1. Idiopathic or immunologically mediated photodermatoses 2. Photoexacerbated dermatoses 3. Agent induced photosensitivity 4. DNA repair defects Photosensitivity induced by agents are secondary reactions to the exposure to some chemicals, called photosensitizers, and to different types of light radiation. Photosensitizers can be classified as exogenous or endogenous. Exogenous agents come from the environment, drugs or other products (both systemic and topical), which undergo structural changes when they come into contact with radiation, causing different skin manifestations as consequence. Differences between phototoxic and photoallergic reactions (both photosensitivity reactions induced by exogenous agents), the clinical approach of each one of them, and available tests that are used to make a diagnosis, especially, photo patch test will be reviewed in this article

Photosensitivity caused by dronedarone: A case report

Dronedarone is a new antiarrhythmic drug for the treatment of nonpermanent atrial fibrillation. Compared with amiodarone, it is regarded as a safe medication due to its structural differences. In this report, we describe a 56-year-old man who developed photosensitivity due to dronedarone. He presented with itchy skin rashes for 1 week. Maculopapular exanthema was localized on the neck, both arms, and both hands, with sparing of the other parts of the body. Dronedarone was prescribed 4 weeks ago when atrial fibrillation occurred. After development of skin rashes, dronedarone was discontinued, and systemic steroid, antihistamine, and topical corticosteroid were administered for 1 week, with improvement in skin rashes. The photopatch test was performed with antiarrhythmic drugs, including dronedarone, amiodarone, and flecainide, 4 weeks after withdrawal of dronedarone. Positive reactions were recorded only to dronedarone at the site exposed to ultraviolet A. He was diagnosed with dronedarone-induced photosensitivity and advised to change the antiarrhythmic medication to others. There have been a few case reports on photosensitivity reactions due to dronedarone, which were diagnosed only by clinical suspicion. However, we suspected photosensitivity and proved it by the photopatch test. Photosensitivity should be considered in patients having skin rashes on the exposed area and taking antiarrhythmic medication, including dronedarone.

Narrow-band ultraviolet B phototherapy regimens for the treatment of chronic actinic dermatitis and analysis of factors influencing treatment compliance / 中华皮肤科杂志

Objective To investigate the optimal regimen of narrow-band ultraviolet B (NB-UVB) phototherapy in the treatment of chronic actinic dermatitis (CAD),and to analyze factors influencing treatment compliance.Methods Demographic data,results of photobiological tests,treatment parameters and clinical responses were collected from CAD patients who received NB-UVB phototherapy in Huashan Hospital affiliated to Fudan University from January 2008 to June 2015,and were reviewed retrospectively.Statistical analysis was done by using two independent samples t-test and chi-square test with SAS9.3 software to compare the clinical data between patients who completed and did not complete the NB-UVB phototherapy.Results A total of 79 CAD patients with Fitzpatrick skin type Ⅳ received NB-UVB phototherapy.Of these patients,61 (77％) completed the whole treatment,while 18 (23％) dropped out because of intolerance to the NB-UVB radiation.Among the 61 patients who completed the treatment,the average initial,final and cumulative radiation doses of NB-UVB were (0.08 ± 0.01) J/cm2,(0.32 ± 0.08) J/cm2and (5.9 ± 2.5) J respectively,and patients received (28 ± 8) times of treatment in average.When the radiation dose went up to 0.30 J/cm2,most skin lesions were cleared in 52 (85％) patients.A total of 19patients received phototesting again after the end of phototherapy.Among 16 patients sensitive to ultraviolet A (UVA) before the treatment,6 had normal minimal erythema dose to UVA (UVA-MED),and another 6 had improved UVA-MED after the treatment.Among 16 patients sensitive to UVB before the treatment,11 got normal UVB-MED and another 3 had improved UVB-MED after the treatment.Univariate analysis showed no significant differences in gender,age,duration of the disease,sensitivity to UVA and UVB radiation,results of photopatch test and patch test between the patients who completed and did not complete the treatment (all P ＞ 0.05).Conclusions The appropriate NB-UVB phototherapy for CAD patients should start at an initial radiation dose of 0.08 J/cm2 in spring and end at a final radiation dose of 0.30 J/cm2 for about 28 sessions,which can effectively reduce the photosensitivity to both UVA and UVB in CAD patients.Additionally,NB-UVB phototherapy can be applied in CAD patients of different gender,age,disease duration and photosensitive condition.

Evaluation of photopatch test allergens for Indian patients of photodermatitis: Preliminary results.

Background: There is a strong need to develop a photopatch test tray suitable for Indian patients of photodermatitis as European/Scandinavian photopatch test trays may not be wholly relevant for them. Aim: We carried out this study using photoallergens relevant in the Indian context to determine their relevance in patients of photodermatitis. Methods: Thirty patients (M:F, 23:7) between 19 and 76 years of age of photodermatitis and 10 controls were patch- and photopatch tested with 20 common photoallergens. In addition, the patients were also (photo) patch tested with articles of daily use as and when these were suspected to be the cause. Results: Forty-three positive reactions to one or more antigens were seen in 22 (74%) patients. Fourteen positive photopatch tests to seven allergens were observed in 10 (33%) patients, and nine (30%) of them had a definite relevance. The most common contact allergen was fragrance mix (FM) (30%), followed by p-phenylenediamine (20%) and Parthenium hysterophorous (17%). The definite relevance of the patch- and photopatch tests could be correlated in 47% of these patients. Conclusions: FM is the most common contact and photocontact allergen among the various photopatch test antigens. Although differences in technique and evaluation make direct comparison between different centers difficult, still photopatch testing remains an integral part and gold standard for the work-up of the photosensitive patients.

Phototoxic Dermatosis among Coal-tar Pitch Workers / 예방의학회지

Interview survey and dermatological examination have been performed to investigate the health problems of workers continuously exposed to coal-tar pitch. The phototoxicity of coal-tar pitch was confirmed by the photopatch tests for six healthy adults. The main results are followings; 1. There was no special history of allergic diseases in both the exposed and non-exposed group. 2. The frequency of the phototoxic dermatosis and the coal-tar acne in the exposed group was significantly greater(p<0.05) than that of the control group. In the exposed group, the phototoxic dermatosis and the coal-tar acne were observed in nine workers(90%) and seven workers(70%), respectively. However, those disease were not observed in the control group. 3. Five results(83%) were positive to the photopatch test for coal-tar pitch 48 hours after UVA irradiation. But the lesion was subsiding 72 hours after UVA irradiation. 4. Malignant cancers were not reported among workers ever exposed to coal-tar pitch. In conclusion, it appears that workers exposed to coal-tar pitch have high risks of phototoxic dermatosis and coal-tar acne. A health policy should be provided to prevent phototoxic dermatosis among coal-tar pitch workers. More studies are required to determine malignancy.

A case of piroxicam-induced photosensitive dermatitis / 영남의대학술지

We report a case of piroxicam-induced photosensitive dermatitis in a 54-year-old female. She had taken oral piroxicam and was exposed to the sunlight on her way home for a few minutes. Several hours after the sun-exposure she developed well-defined, confluent, erythematous plaques and numerous vesicobullae with pruritus and prickling sensation on the sun-exposed areas. A phototest was done on her first visit. The minimal erythemogenic dose (2 J/cm²) of ultraviolet (UV) A was markedly decreased whereas that of UVB was within a normal limit. Visible light irradiation for 30 minutes did not cause skin lesions. Six months after the initial skin lesions, a photopatch test with 1% and 10% piroxicam solution followed by UVA (10 J/cm²) irradiation showed positive responses on both concentrations.

Two Cases of Piroxicam-Induced Photoallergic Dermatitis / 대한피부과학회지

Piroxicam is a new nonsteroidal anti-inflammatory drug(NSAID) and widely used in the management of rheumatoid arthritis and osteaorthritis. We experienced. two cases of photosensitive dermatitis developed while taking piroxicam. Both had pruritic and eczematous skin lesions on sun-exposed areas and showed positive reactions to 0. 1 % piroxicam solution in photopatch test in contrast with control group, which suggest a photoallergy mechanism. To our knowledge, these are the first reported cases in the Korean literature.