[Occurrence of pterygium inversum unguis in an adult population]

Pterygium inversum unguis (PIU) is a digital anomaly characterized by adherence of the subungueal tissue to the ventral surface of the distal nail plates. Universal medical literature in ten years reported 24 cases. The foresight that this anomaly could be more frequent, although unnoticed, led us to perform a survey through a systematic digital checking of all patients who were examined by us, in a 8 month period. In this period 2,000 clients were examined, 1,000 being of the female sex and 1,000 of the male sex. Eight cases of PIU of hands, with no familiar trait were diagnosed, 6 of them in females and 2 in males. From the cases in males, 1 was of the idiopathic congenital type and the other was of the secondary type (post-traumatic). From the cases identified in females, 5 were of the idiopathic type (4 acquired and 1 congenital) and 1 was of the secondary type (dermatomyositis). PIU was diagnosed in 8 of the 2,000 adult patients examined by us, reaching 0.4% in frequency. The final result was in accordance with our previous opinion that is not uncommon the incidence of the PIU allowing us to assemble in a short period of time a number of cases larger than any other survey found in medical literature.