Evolving Pattern with Age of Cutaneous Signs in Neurofibromatosis Type 1: a Cross-sectional Study of 728 Patients

Background: Neurofibromatosis type 1 is fully penetrant by the age of 8 years, and 3 criteria of diagnosis are dermatological: café-au-lait spots (CLS), intertriginous freckling and neurofibromas (NF).

Objectives: The aim of our study was to determine the evolving pattern of cutaneous manifestations during adulthood.

Methods: Phenotypic data of patients seen in our center between March 2003 and December 2009 were studied. Patients were classified in 10-year groups. Following clinical characteristics, the number of CLS and the number of cutaneous and subcutaneous NF were compared according to age.

Results: 728 subjects, 404 females and 324 males (mean age of 32.4 years, range 6-80 years) were studied. Four hundred eighty-nine patients were over 20 years old (67%). The number of CLS (small or large) was significantly decreased with age while the number of cutaneous and subcutaneous NF was strongly increased (p < 0.001).

Conclusions: The decrease in CLS with age has not been previously reported while an increase in the number of NF is well described during puberty and pregnancy and with age.