Characteristics and Prognosis of Idiopathic Solar Urticaria

Abstract

Background: As little has been published on the course of idiopathic solar urticaria (SU) patients cannot receive comprehensive prognostic advice. Objective: To determine the prognosis and photobiological characteristics of idiopathic SU. Design: Historical cohort study, with inception cohort followed up from time of diagnosis. Follow-up for a median of 4 years (range, 3 months to 26 years) after diagnosis. Setting: Tertiary referral center for the investigation of photodermatoses in Scotland. Patients: The study included 87 patients, 61 (70%) of whom were female, with phototest-confirmed idiopathic SU between 1975 and 2000. Sixty patients (69%) were followed up clinically, and 25 patients (29%) were phototested on 2 or more occasions. Interventions: Investigations at time of diagnosis included monochromator phototesting. Further monochromator phototesting was performed in those patients in whom it was clinically indicated (select subgroup), and all patients who could be traced received a follow-up questionnaire. Main Outcome Measures: Characteristics of SU, responsible wave bands, and prognosis for clinical resolution. Results: The prevalence of idiopathic SU in Tayside, Scotland, is estimated to be 3.1 per 100000. Action spectra were typically broad, with 63% reacting to more than 1 wave band, and the most common provoking wavelengths were the longer UV-A and the shorter visible ones. The majority of subjects were affected perennially (68%), by radiation transmitted through glass (83%) and thin clothing (76%). Coexistent polymorphic light eruption occurred in 20 patients (23%), and another photodermatosis occurred in 6 patients, 3 of whom had chronic actinic dermatitis. In those with SU alone, the mean age at onset was 41 years. The probability of clinical resolution at 5 and 10 years after diagnosis was 0.12 (95% confidence interval, 0.06-0.24) and 0.26 (95% confidence interval, 0.15-0.43), respectively. Conclusion: Idiopathic SU is a chronic disease. The majority of this cohort was still affected after 5 and 10 years.

Solar urticaria: Clinic, diagnostic, course and therapy management in 27 patients

“…In patients 1 to 26, the median age of initial manifestation was 35 years. This is in good agreement with major case series from several countries published in recent years [3–8, 41–44]. Similar to our study, the gender distribution in the recently published major case series showed that female patients are predominantly affected: Beattie et al.…”

“…Similar to our study, the gender distribution in the recently published major case series showed that female patients are predominantly affected: Beattie et al. [4] 61 vs. 26, Du‐Than et al. [5] 43 vs. 18, Haylett et al.…”

Real‐life experience in the treatment of solar urticaria: retrospective cohort study

“…Only 1 patient in our series had a concomitant photodermatosis (allergic photocontact dermatitis), whereas none of the 40 excluded patients with other photodermatoses had SU. Although Beattie et al . found coexistent polymorphic light eruption in 23% of 87 patients with SU, others have reported a low prevalence of concomitant photodermatoses, in accordance with our findings …”

“…Previous studies of SU reported a female predominance and highest rate of occurrence in the third and fourth decades of life . In accordance with this, two‐thirds of our cohort were female and the median patient age was 25 years.…”

Treatment of solar urticaria using antihistamine and leukotriene receptor antagonist combinations tailored to disease severity

“…In the present series of patients, all patients displayed sensitivity to visible light, three patients were also sensitive to UVA, and one demonstrated sensitivity to all three spectra evaluated. Although sensitivity to visible light was more frequent than in other series , our finding of UVB sensitivity in only one patient is in accord with the infrequent occurrence of UVB induced SU reported by others.…”