LAUSR

YNS typically involves a triad of thickened yellow nails, primary lymphedema and respiratory manifestations, which are variable in their presentation. It is an acquired condition of unknown cause, and rarely presents below the age of 50. Only a few hundred cases have been reported in the literature, with an estimated prevalence of less than 1 in 1 000 000 and those reported arising mostly in the sixth decade of life, with no sex predominance. A very rare paediatric variant is also reported. YNS may be present at birth (congenital) or develop before the age of 10 years. Among the three clinical YNS clinical findings (yellow thickened nails, respiratory tract involvement and lymphedema), only two are required to diagnose YNS, but it is difficult to use the diagnostic term of YNS without the nail changes being evident. The complete triad is present only in 27 to 60% of the patients. Although some familial cases have been reported, there is no known genetic cause. It is a clinical diagnosis.