Severe and refractory solar urticaria treated with intravenous immunoglobulins: a phase II multicenter study.

BACKGROUND

Retrospective data have suggested the effectiveness of intravenous immunoglobulins (IVIG) for solar urticaria (SU).

OBJECTIVE

We sought to prospectively assess the efficacy of IVIG for SU.

METHODS

We conducted a multicentric phase II study to test the efficacy of a single course of IVIG (2 g/kg) in patients with severe and refractory SU. The primary outcome was remission of SU on phototesting at 12 weeks after IVIG treatment. Secondary objectives included clinical remission, improved quality of life, and 50% improvement in disease intensity as measured on a visual analog scale.

RESULTS

Of the 9 patients who received IVIG injection, 2 showed remission of SU on phototesting, corresponding to a response rate of 22.2% (95% confidence interval 2.8%-60.0%). In all, 6 patients (67%) showed at least 1 response criterion after 4 weeks and 5 (56%) after 12 weeks. Response was maintained after 24 weeks for 2 patients and after 48 weeks for 1 patient. About half of the patients (56%) had moderate to severe headache.

LIMITATIONS: Lack of control arm and small number of patients are limitations.

CONCLUSION

A single course of IVIG appears insufficient to obtain prolonged significant control of SU; future evaluation of different schedules of IVIG administration is warranted.