Prevalence of Raynaud's phenomenon in Japanese males and females.

In order to estimate the prevalence rate of Raynaud's phenomenon in the Japanese population, 1875 males and 1998 females were interviewed by medical doctors, aided by a typical photograph of Raynaud's phenomenon. The prevalence rates were 3.3% in males and 2.5% in females. Approximately 60% of the male cases of Raynaud's phenomenon were presumed to be caused by vibration syndrome or trauma to the fingers. Prevalence rates excluding these two causes were 1.2% in males and 2.2% in females. The male:female ratio of these prevalence rates was 1:1.9. The prevalence rate for males increased with age, while that for females tended to decrease. The male:female ratio for subjects under 50 years old was 1:5.2 and for those 50 years old or older the ratio was 1:1.1. The prevalence rates of symptoms limited to finger whitening, excluding cases caused by vibration syndrome or trauma, were 1.0% in males and 1.8% in females. Both of these prevalence rates were lower than those of male and female Caucasians.