Estudio de la dosis eritematosa mínima en una serie de urticaria solar / Study of Minimal Erythema Dose in a Series of Solar Urticaria

Antecedentes La dosis eritematosa mínima (DEM) reducida es una reacción anormal a la luz según el fototipo de piel y que se determina mediante fototest. La DEM es reducida o anormal en algunas fotodermatosis. Sin embargo, no hemos encontrado información sobre la DEM reducida en pacientes con urticaria solar (US), enfermedad que cursa con urticaria tras la exposición al sol. Objetivo Determinar la DEM en una serie de pacientes con US. Métodos Llevamos a cabo un estudio prospectivo de casos de US diagnosticados en nuestro departamento entre enero de 2007 y diciembre de 2017, a través de anamnesis o por provocación mediante exposición a la luz solar natural o a fuentes de luz artificial. De acuerdo con el protocolo del Grupo Español de Fotobiología, a las 24 horas se llevó a cabo la lectura del fototest en todos los pacientes. Se recopilaron las variables relativas al paciente (edad, sexo, fototipo), enfermedad (tiempo de evolución, espectro de activación) y otras relacionadas con la posible DEM reducida (autoanticuerpos, medicación fototóxica). Resultados Se estudiaron 25 pacientes, de los cuales, seis (24%) presentaron una DEM anormal, el 83% de ellos eran hombres, y el 50% mostraba el espectro de acción en el rango de la radiación UVB. Conclusión Hasta en una cuarta parte de los pacientes con US se puede observar la DEM anormal. Esta circunstancia podría tener implicaciones en la selección de los pacientes y en los protocolos para el tratamiento con fototerapia (AU)

Background Reduced minimal erythema dose (MED) is an abnormal erythematous reaction to light according to the skin phototype, which is determined by phototest. MED is reduced or abnormal in some photodermatoses. However, we have not found information about reduced MED in patients with solar urticarial (SU), a condition which causes hives after sun exposure. Objective To determine MED in a series of patients with SU. Methods We conducted a prospective study of SU cases diagnosed in our department between January 2007 and December 2017, either by anamnesis, provocation with natural sunlight or provocation with artificial light sources. In all patients, a phototest with reading at 24 h was performed according to the protocol of the Spanish Group of Photobiology. Variables related to the patient (age, sex, phototype), disease (time of evolution, action spectrum) and others related to possible reduced MED (autoantibodies, phototoxic medication) were collected. Results Twenty-five patients were studied. Six patients (24%) had abnormal MED. Eighty-three percent of patients with abnormal MED were men, and 50% had action spectrum in UVB. Conclusion Abnormal MED can be seen in up to a fourth of the patients with SU. This could have implications in the selection of patients and protocols for treatment with phototherapy (AU)

Induction of Light Tolerance Using Narrowband UV-B in Solar Urticaria. / Inducción de fototolerancia con ultravioleta B de banda estrecha en urticaria solar.

INTRODUCTION: Solar urticaria is an uncommon photodermatosis. First-line treatment is with antihistamines; second-line treatment includes induction of light tolerance using UV phototherapy. OBJECTIVES: We aimed to describe and evaluate the effectiveness of a desensitization protocol with narrowband UV-B in patients with solar urticaria. MATERIAL AND METHODS: We performed a retrospective study of patients with solar urticaria with an action spectrum in the UV-A range, the visible light range, or both who had received therapy with narrowband UV-B for induction of light tolerance. Short courses of treatment were administered (<20 sessions, 3 per week) during spring. The initial dose was determined according to the skin type. The Skindex-29 was administered before treatment and after summer; a nonvalidated questionnaire was also administered after summer to evaluate disease activity and satisfaction with treatment. RESULTS: We included 8 patients with an action spectrum (4 with visible light and 4 with UVA plus visible light). Seventeen courses (1-6 per patient) were administered per year. The number of sessions per year ranged from 11 to 20. The mean dose of narrowband UV-B per course was 7.45J/cm2. No patients experienced flares or adverse effects during treatment. The response was satisfactory in 6 patients. The improvement in the overall Skindex-29 score was greater than 20% in 78.6% of cases. The improvement in the function and symptoms subscales was over 20% in 71% and 64% of cases, respectively. CONCLUSION: Induction of light tolerance with narrowband UV-B in solar urticaria is safe and effective in a high percentage of patients.

Response to Omalizumab in Solar Urticaria: Report of 3 Cases. / Respuesta a omalizumab en 3 casos de urticaria solar.

We report 3 cases of solar urticaria in which there was no response or limited response to first-line treatments with high-dose H1 antihistamines or phototherapy. The patients were then treated with omalizumab. Symptoms improved in 2 patients, whose tolerance to sunlight increased considerably; quality of life clearly improved for 1 of these patients. The third experienced no improvement and developed a mild local reaction to the injected medication. We conclude that omalizumab may offer a potentially safe, useful alternative for patients with solar urticaria who do not respond to conventional therapy.

Omalizumab in the Treatment of Chronic Inducible Urticaria. / Omalizumab en el tratamiento de la urticaria crónica inducible.

Omalizumab is a recombinant humanized monoclonal antibody that inhibits immunoglobulin E. It has been approved for the treatment of severe asthma and chronic spontaneous urticaria refractory to other treatments. Its use in the management of chronic inducible urticaria (a type triggered by certain stimuli) is still considered off-label, although this use has been discussed in some consensus papers. This review brings together case reports and case series describing the use of omalizumab to treat chronic inducible urticaria. We analyze the most important aspects of the cases and the outcomes reported. The results seem to position omalizumab as a potentially effective, safe treatment alternative in some cases of chronic inducible urticaria.

Solar urticaria: Epidemiology and clinical phenotypes in a Spanish series of 224 patients. / Urticaria solar. Epidemiología y fenotipos clínicos en una serie española de 224 pacientes.

BACKGROUND: Solar urticaria is a chronic inducible urticaria also classified as an idiopathic dermatosis. The objective of this paper is to define the phenotypic characteristics of solar urticaria and to evaluate its incidence. MATERIAL AND METHOD: This was a retrospective multicenter study in which data were gathered on the epidemiology and clinical, photobiologic, laboratory, and therapeutic characteristics of solar urticaria. RESULTS: A total of 224 patients (141 women and 83 men) were included from 9 photobiology units. The mean age of the patients was 37.9 years (range, 3-73 years). A history of atopy was detected in 26.7%, and the most common presentation was allergic rhinitis (16.5%). Clinical signs were limited to sun-exposed areas in 75.9% of patients. The light spectrum most commonly implicated was visible light only (31.7%), and in 21% of cases it was only possible to trigger solar urticaria with natural light. The treatments most widely used by photobiology experts were oral antihistamines (65.46%), followed by different forms of phototherapy (34%). Complete resolution was observed most often in patients with solar urticaria triggered exclusively by visible or natural light, with statistically significant differences with respect to other wavelengths (P<.05). No increase in the annual incidence of solar urticaria was observed. CONCLUSIONS: We have presented the largest series of solar urticaria published to date. The epidemiological, clinical, and photobiologic findings confirm previously reported data, although there was a particularly high rate of negative phototests in our series. Reactivity exclusively to visible or natural light was associated with a higher probability of resolution. No increasing trend was observed in the annual incidence.