Malignancy and interstitial pneumonitis as fatal complications in dermatomyositis.

By sending questionnaires to the major dermatological clinics in Japan, we examined the outcome and causes of death in 182 cases of dermatomyositis (DM) observed between 1983 and 1987. The mortality rate in adults was 26.7%. Associated malignancy occurred in 47 cases (25.8% of adults), and 16 of them died of neoplasms. In contrast to 43 carcinomas, only 1 patient died of lymphoma. Associated interstitial pneumonitis (IP) appeared in 31 cases. IP started simultaneously or within 6 months after the diagnosis of DM in the majority of these cases. Of the 13 fatal cases due to IP, 8 died of respiratory failure within two months of the onset of lung disease. In the malignancy group, periungual erythema was noted in a higher proportion. Raynaud's phenomenon was more frequently noted in the IP group. DM overlapped with other collagen diseases in 14 cases.