A new retrospective analysis presented at the 2025 American Academy of Allergy, Asthma, and Immunology/World Allergy Organization Joint Congress has provided important insights into the characteristics and treatment of solar urticaria, a rare photodermatosis condition.
Patient Demographics and Symptom Presentation
The study, led by Dr. Neha Christian from Barts Health NHS Trust, London, examined 14 patients with solar urticaria. Women comprised the majority of cases (57.14%), highlighting a gender-based prevalence. The condition manifested rapidly, with half of the patients experiencing symptoms within 5 minutes of light exposure, and most (71.42%) showing resolution within 2 hours.
The analysis revealed that 57.14% of patients experienced cutaneous symptoms, while 21.42% developed angioedema, and 28.56% reported systemic symptoms. Notable comorbidities included atopy in 42.86% of patients, and vitamin D deficiency was observed in 50% of the cohort.
Trigger Identification and Treatment Response
Phototesting identified several key triggers:
- UVA alone: 35.71% of cases
- UVA + Visible Light: 28.57% of cases
- Visible Light alone: 14.28% of cases
- UVB alone: 14.28% of cases
- Combined UVB+UVA+Visible Light: 7.14% of cases
Treatment Effectiveness and Management Strategies
All patients showed partial improvement with a combination of antihistamines and sunscreen. However, montelukast and H2 blockers proved ineffective. Omalizumab emerged as a promising treatment option, with patients requiring either:
- 150mg every 28 days (5 patients)
- 300mg every 28 days (9 patients)
Clinical Implications
The findings underscore the importance of comprehensive photoprotection strategies. Standard sunscreens alone proved insufficient against visible light triggers, suggesting the need for specialized protection. The researchers recommend tinted sunscreens containing iron oxides and pigmentary titanium dioxide for better management of visible light sensitivity.
The study's results emphasize the need for early consideration of omalizumab in treatment-resistant cases, given its demonstrated effectiveness in achieving symptom control. This insight provides valuable guidance for clinicians managing patients with this challenging photodermatosis.
