Hereditary polymorphic light eruption in Canadian Inuit.

Twelve Canadian Inuit patients from the Keewatin District of the Northwest Territories were found to have hereditary polymorphic light eruption. The clinical manifestations were similar to those described in the North American Indian, with a photodermatitis occurring in the sunlight-exposed area. The onset occurred prior to the age of 15 years in 70% of subjects, and the condition was seasonally recurrent, starting in February and lasting until September. Patients demonstrated improvement on a combined regime of local therapy and oral trioxalen. Seventy-five percent of patients had a family history of photosensitivity, suggesting an autosomal dominant trait with incomplete penetrance. Indian ancestry was not demonstrated in these patients.