Idiopathic acquired true leukonychia: a unique entity.

Idiopathic acquired true leukonychia is a rare benign acquired disorder that typically affects adults. Diagnosis is made clinically, with investigations required to exclude any underlying cause. The cause of this condition is largely unknown, yet it understandably causes significant anxiety to patients due to concerns about underlying systemic disease. We report a case of idiopathic acquired true leukonychia totalis in a healthy 20-year-old man. Intermittent complete whitening of some of the fingernails was reported over a 7-year period. No underlying medical cause or laboratory abnormality was identified. This case highlights the importance of considering idiopathic acquired true leukonychia as a differential diagnosis of nail whitening. In addition, increased awareness of this unique entity is needed for patient reassurance, as well as avoidance of unnecessary investigations and prolonged systemic treatment.