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

BACKGROUND AND OBJECTIVES: Solar urticaria is a rare photodermatosis, the diagnosis and therapy of which have not yet been standardized. The aim of this research was to use innovative radiation sources for diagnostics with defined and reproducible emission spectra and doses. A uniform therapy step scheme was to be created.

PATIENTS AND METHODS: In a longitudinal study, 27 patients with solar urticaria were examined over 13 years. With a characteristic anamnesis, the diagnosis was confirmed with phototesting (photoprovocation) from various radiation sources (UVB, UVB311nm, UVA, UVA-1, green light, red light) and a therapy step scheme was designed consisting of light protection, antihistamines, rush hardening with UVA-1, and administration of omalizumab.

RESULTS: Action spectrum: UVB 44 %, UVA 70 %, UVA-1 89 %, green light 37 % and red light 22 %. Rush hardening with subsequent maintenance therapy was performed on 20 patients, 17 of whom were hereby adequately protected. In three further patients, omalizumab was additionally administered.

CONCLUSIONS: Phototesting with UVB, UVB311nm, UVA, UVA-1, and visible light with innovative radiation sources is uniformly possible in every major skin clinic. With the help of the therapy step scheme the patients can be adjusted well. Rush hardening with UVA-1 is a safe method to help the patients during the sunny season. Omalizumab as the last therapy option is effective, but currently only possible in off-label use.