Urticaria is one of the most common dermatological conditions with diverse clinical
presentations and causes. Solar urticaria (SU) is a rare subset of physical urticaria, where
symptoms are induced by direct exposure of the skin to sunlight. As little as 5 minutes of
sun exposure can cause flares and whealing on exposed skin sites, accompanied by severe
itching. The wavelengths of radiation causing the eruption (i.e. the action spectrum) are in
the ultraviolet or visible light range. Initially described by Merklen in 1904, SU may have a
very sudden and dramatic onset, and then rapidly disappear once the exposure ceases. A
delayed form of SU has also been reported, although this is extremely rare. Information on
the pathophysiology of SU is limited and symptoms are confined to areas of the body exposed
to direct sunlight. The condition can be very distressing and severely impair the
individual's ability to go outdoors and to tolerate indoor lighting. The standard therapy,
i.e. oral antihistamines, is only partially effective and may provide little worthwhile
relief of symptoms.
This pilot study is proposed to evaluate implants containing 16mg CUV1647 as a prophylactic
treatment for patients with SU. The effectiveness of CUV1647 will be assessed by determining
the minimum urticarial dose before and after treatment.