Most cases from South Africa, and all 4 cases from America, have occurred in black individuals. Cases have been reported among West Indians living in England. No sex predilection has been demonstrated in several large series. The report of Sardinian patients had 22 males and 20 females. In the review of 42 cases from Sardinia, the average age of onset was estimated to be 3-7 years of age.
Patients usually are completely asymptomatic.
In one review of 64 cases, all patients were undergoing assessment for an underlying medical condition and the lesions of PR were noted incidentally. Few could remember the duration of the lesions, which varied from 1 week to 2 years. They range from 0.5-20 cm in size and generally are isolated, but merging of lesions will result in a polycyclic configuration. Several lesions usually are present, ranging from 4-80. One patient had over 100 lesions.