Mee’s lines is the eponym for linear leukonychia, presenting as transverse white bands of the nail plate. It is due to interrupted growth of the nail matrix, resulting in parakeratosis of the nail plate. These lesions grow out with the nail and do not blanche with pressure. This is in contrast to Muehrcke’s lines, appreciated in patients with hypoalbuminemia,, causing vascular congestion of the nail bed. These stay fixed in their clinical appearance, blanching when the nail bed is compressed.
Ask any resident before their board exam what Mee’s lines are associated with and their knee-jerk response would be arsenic ingestion. Mee’s lines may also be appreciated with Hodgkin disease, CHF, leprosy, malaria, carbon monoxide poisoning, and other systemic insults (1). Campbell et al, present the case of anagen effluvium secondary to thallium poisoning, reminding us in their discussion that thallum may also cause Mee’s lines (2).
Kim et al present a 49 year-old man with lung cancer, who developed Mee’s lines alternating with Beau’s lines on the fingernails and toenails, following the initiation of chemotherapy with paclitaxel-cisplatin at 3 week intervals (3).
The classic teaching is that Mee’s lines do not present with depressions of the nail plate. The fact is that Mee’s lines, Beau’s lines, and onychomadesis are all on the same pathophysiologic spectrum, as beautifully illustrated by Kim’s case. Nail that concept in your memory bank.
- Fawcett RS, et al. Nail abnormalities: Due to systemic diseases. Am Fam Phys 2004; 696: 1417-24.
- Campbell C, et al. Anagen effluvium caused by thallium poisoning. JAMA Dermatology 2016; 152: 724-6
- Kim IS, et al. Nail change after chemotherapy: simultaneous development of Beau’s lines and Mee’ s lines. Ann Dermatol 2012; 24: 238-9