[Sarcoidosis in Iceland 1981-2003]

To investigate the incidence of sarcoidosis in Iceland, its clinical manifestations and potential environmental influences.

All histopathological diagnoses of non-necrotizing granulomas generated in Iceland during the period 1981-2003 were reviewed with respect to a diagnosis of sarcoidosis. Further, patients were identified by searching hospital discharge diagnoses at the University Hospital in Reykjavik and the Regional Hospital in Northern Iceland. Only histologically verified cases were included.

A total of 235 patients were found with histopathologically proven sarcoidosis. Limited to patients verified by tissue diagnosis, the annual incidence of sarcoidosis is 3,84/100.000/year. The incidence was found to be 2,8/100,000/year during the first half of the investigation period and 5,0/100,000/year during the second. This rate is lower than in other Nordic countries. There were 122 women and 113 men. The mean age at diagnosis was 50,8 years for women and 47,5 for men. The mean age at diagnosis was higher in Iceland than elsewhere. Clinically, respiratory symptoms predominated. Ocular symptoms and erythema nodosum are rare, and life-threatening cardiovascular and neurological manifestations are distinctly unusual.

The low incidence is undoubtedly due to the strict inclusion criteria in the present study, i.e. only those with a tissue diagnosis were included. We have no explanation as to the higher age at diagnosis in Iceland than elsewhere. Registration of possible environmental factors and clinical evaluation may be improved.