White nail changes are broadly called leukonychia: “leuko” meaning white and “nychia” referring to the nail. Scattered or single asymptomatic cloudy white nail lesions occurring without other associated skin or nail disorders are more specifically called punctate leukonychia.
Punctate leukonychia is theorized to be caused by trauma at the proximal nail matrix, affecting the developing nail.1 The trauma may result from aggressive nail care practices or damage to the cuticle. In many cases, there is no history of known trauma. For this patient with multiple lesions, who performed manual work, multiple small traumas may have induced the punctate leukonychia.
Other causes of leukonychia include superficial onychomycosis (in which discoloration may be whiter than the usual yellow-brown), renal disease, and arsenic toxicity.1 Arsenic toxicity causes transverse leukonychia in a band-like fashion, since it is a systemic insult to the growing nails. Longitudinal leukonychia is due to a more localized insult to the nail matrix, causing the white lines to grow out with the nail along the axis of the digit. Other than avoiding trauma, there is no treatment needed or recommended for punctate leukonychia.
The patient was counseled on the benign nature of his punctate leukonychia and assured that no treatment was necessary.
Photo courtesy of Daniel Stulberg, MD. Text courtesy of Daniel Stulberg, MD, FAAFP, Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque.