Fast Five Quiz: Fingernail and Toenail Conditions

William James, MD


February 07, 2020

The two transverse bands originally described by Muehrcke run parallel to the lunula. Muehrcke lines may be evident on both fingernails and toenails. The bands are separated from each other and from the lunula by areas of normal pink nail; they are not palpable and do not indent the nail itself. The distal white band may be wider than the proximal band. The lines are usually found on the second, third, and fourth fingernails; they rarely occur on the thumbnail.

A complete and detailed history is necessary and should include questions concerning occupation and medications. Attention to the chronologic sequence of the events related to the nail abnormality is important. A personal history and a review of systems may also provide important clues to the etiology of the nail changes. Nail changes in patients taking medications for cancer treatment—particularly taxanes and epidermal growth factor receptor (EGFR) inhibitors—may cause pain and functional impairment; Muehrcke lines are not linked with nail symptoms, however.

Obtain appropriate laboratory tests as indicated by the history features and the physical examination findings. The most important test is serum albumin measurements. The appearance of the paired, narrow, white bands on the fingernails is typically correlated with a serum albumin level < 2.2 g/100 mL. The lines have been shown to persist with chronic hypoalbuminemia and to disappear when the serum albumin level rises > 2.2 g/100 mL. Total serum protein levels, serum chemistry enzyme levels, a urine analysis, and a CBC count are also useful tests. Treatment should be undertaken in a case-specific manner. In patients presenting with paired, white, transverse lines due to a serum albumin deficiency, albumin infusions to raise the serum level aid in the disappearance of Muehrcke lines. Treatment of the underlying disease additionally aids in correcting the abnormal serum albumin levels. Large amounts of multivitamin injections do not appear to have any effect on the appearance of the white bands in the fingernails.

Read more about Muehrcke lines of the fingernails.

This Fast Five Quiz was excerpted and adapted from the Medscape Drugs & Diseases articles Onychomycosis, Ingrown Nails, Nail Psoriasis, Clubbing of the Nails, and Muehrcke Lines of the Fingernails.

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