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

ANTECEDENTES: La urticaria solar es una urticaria crónica inducible física clasificada también como fotodermatosis idiopática. El objetivo de este trabajo es definir las características fenotípicas y valorar su incidencia. MATERIAL Y MÉTODO: Estudio multicéntrico retrospectivo en el que recogen datos epidemiológicos, características clínicas, fotobiológicas, analíticas y terapéuticas. RESULTADOS: Se ha incluido a 224 pacientes procedentes de 9 Unidades de Fotobiología. La distribución por sexos correspondió a 141 mujeres y 83 varones con una edad media al diagnóstico de 37,9 ańos (rango 3-73). El 26,7% presentaba antecedentes de atopia, con la rinitis alérgica como la manifestación más frecuente (16,5%). Un 75,9% de los pacientes refería clínica solo en zonas fotoexpuestas. El espectro implicado con más frecuencia fue la luz visible aisladamente (31,7%). En el 21% la urticaria solar solo fue posible desencadenarla con luz natural. El tratamiento más empleado por los expertos fueron los antihistamínicos por vía oral (65,46%) seguido por diferentes modalidades de fototerapia (34%). La resolución completa se observó con mayor frecuencia en urticaria solar desencadenada exclusivamente por luz visible o luz natural, con diferencias estadísticamente significativas (p < 0,05) con respecto a otras longitudes de onda. No se observa un incremento de la incidencia anual. CONCLUSIONES: Presentamos la serie de urticaria solar más larga hasta ahora publicada. Las características epidemiológicas, clínicas y fotobiológicas confirman los datos ya conocidos, aunque en nuestra serie destaca un alto índice de fototest negativos. La reactividad exclusiva a luz visible o luz natural se asocia a mayores probabilidades de resolución. No se observa una tendencia al aumento en la incidencia anual

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

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.