Solar Urticaria More Prevalent in Women, UV and Visible Light Both Common Triggers

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A new retrospective analysis has characterized solar urticaria and its manifestations, with findings including higher prevalence among females and identifying common triggers.¹

These findings will be presented at the 2025 American Academy of Allergy, Asthma, and Immunology/World Allergy Organization Joint Congress, February 28-March 3, in San Diego, California, by lead investigator Neha Christian, MD, Barts Health NHS Trust, London, United Kingdom.

“Solar urticaria is a rare photodermatosis characterized by rapid urticarial lesions following exposure to specific light wavelengths, primarily ultraviolet (UV) and visible light (VL) within electromagnetic spectrum. This study retrospectively reviewed 14 patients with solar urticaria, clinical characteristics and treatment response,” Christian and colleagues wrote.¹

The retrospective cohort analysis had a slightly greater proportion of female participants (n = 8/14; 57.14%). Participants had rapid symptom onset within 15 minutes (50% within 5 minutes) and generally fast resolution (71.42% within 2 hours). Around half (n = 8; 57.14%) had cutaneous symptoms, a small proportion had angioedema (n = 3; 21.42%) and a small proportion had systemic symptoms (n = 4; 28.56%). Less than half of the participants (n = 6; 42.86%) had history of atopy (6/14) and 50% (n = 7) had insufficient vitamin D levels.

The investigators identified UVA (n = 5; 35.71%) and UVA + VL (n = 4; 28.57%) as the most common triggers with phototesting, followed by VL in 2 (14.28%), UVB in 2 (14.28%), and UVB+UVA+ VL in 1 (7.14%). All participants experienced partial relief with antihistamines and sunscreen, but montelukast and H2 blockers were unhelpful. With the use of omalizumab treatment, 5 patients achieved symptom control at 150 mg every 28 days, and 9 required a 300 mg dose to achieve symptom control.¹

“The findings suggest that solar urticaria is more prevalent in females, with a subset experiencing angioedema and systemic symptoms. UVA and visible light are most common triggers. Standard sunscreens are not effective against visible light, tinted sunscreens containing iron oxides and pigmentary titanium dioxide can be considered. Early consideration of omalizumab is recommended as it appears to be an effective treatment,” Christian and colleagues concluded.¹

Other research on urticaria being presented at the AAAAI meeting found that barzolvolimab treatment yielded marked and sustained improvements in urticaria control and quality of life in patients with chronic spontaneous urticaria (CSU) refractory to antihistamines.¹

Participants in the 150mg Q4W groups had mean baseline UCT scores of 3.7 (standard deviation [SD], 2.5) and participants in the Q8W groups had mean baseline UCT scores of 3.0 (SD, 2.6), indicating poorly treated urticaria in both dosage groups. The investigators found that barzolvolimab improved UCT with a mean change from baseline at 52 weeks of 10.5 (SD, 3.9) in the Q4W groups and 9.4 (SD, 5.0) in the Q8W groups.²

Participants in the 150mg Q4W groups had mean baseline DLQI scores of 15.7 (SD, 7.6) and participants in the 300 mg Q8W groups had mean baseline DLQI scores of 17.4 (SD, 7.5), indicating a very large impact of disease on QoL. The investigators found that barzolvolimab improved DLQI with a mean change from baseline at 52 weeks of -14.2 (SD, 7.3) in the 150mg Q4W groups and -15.0 (SD, 8.5) participants in the 300 mg Q8W groups.²

REFERENCES

1. Christian N, Rutkowski C, Grattan C, et al. Solar Urticaria: A Retrospective Analysis of 14 cases. Presented at: 2025 AAAAI/WAO Joint Congress, February 28-March 3. Abstract L39

2. Maurer M, Metz M, Kobielusz-Gembala I, et al. Barzolvolimab Improves Urticaria Control and Quality of Life in Patients with Chronic Spontaneous Urticaria: 52-Week Data. Presented at: 2025 AAAAI/WAO Joint Congress, February 28-March 3. Abstract L11.