Overexposure to ultraviolet radiation in solar urticaria

A man in his 50s was diagnosed with solar urticaria following monochromated light testing that demonstrated exquisite photosensivity to ultraviolet (UV) A, UV B (UVB) and visible light.Treatment options for this photodermatosis are limited; UVB phototherapy is one modality that can be appropriate in some patients. This is administered at very low doses in a controlled environment to induce skin hardening.¹ To self-treat his condition, the patient used a commercial sunbed on two occasions several days apart. He noted an immediate flare of solar urticaria after first use with associated dizziness. Following the second use, he felt generally unwell and was witnessed to lose consciousness and displayed jerky movements of his limbs while a passenger in a car. Investigations including a head MRI and an EEG were normal; an anoxic seizure caused by a flare of solar urticaria was later confirmed.Solar urticaria is a rare photodermatosis that is poorly understood and difficult to treat. The condition has a significant impact on the quality of life of patients. Severe cases can be associated with systemic symptoms that could be life-threatening.