Advertisement

Muehrcke's Lines

      A 29-year-old woman with no significant medical history developed anasarca over the course of approximately 2 weeks. On the basis of renal biopsy, a diagnosis of minimal change disease was made. Her nephrotic syndrome was poorly responsive to steroid therapy, and despite high doses of prednisone of up to 120 mg/d, her serum albumin and proteinuria remained 1 g/dL and 10 g/d, respectively. Approximately 1 month after the onset of her symptoms, she developed transverse, nonpalpable, white lines on all her fingernails (Figures 1 and 2) . These nail changes are consistent with a diagnosis of Muehrcke's lines (Figure 1).
      Figure thumbnail gr1
      Figure 1Muehrcke's lines in a patient with nephrotic syndrome and hypoalbuminemia.
      Dr Robert Muehrcke
      • Muehrcke R.
      The finger-nails in chronic hypoalbuminaemia: a new physical sign.
      first described this novel clinical finding in an article published in the British Medical Journal in 1956. He identified a total of 32 patients with paired white bands on the fingernails. Of these 32 patients, 23 had nephrotic syndrome and another 9 had hypoalbuminemia from other causes. Muehrcke observed that the lines appeared only in patients with serum albumin levels less than 2.2 g/dL. In this article, he also described 4 patients with these lines treated with intravenous albumin or corticosteroids. In each of these patients, the lines disappeared after the serum albumin increased to greater than 2.2 g/dL. Muehrcke attributed this physical finding to “chronic nutritional deficiency of albumin” and thus suggested that its presence could be used to distinguish between hypoalbuminemia and cardiac dysfunction in the edematous patient (Figure 2).
      As observed by Muehrcke more than 50 years ago, Muehrcke's lines are transverse, paired, white lines on the fingernails that span the entire breadth of the nail and run parallel to the distal lunula.
      • Muehrcke R.
      The finger-nails in chronic hypoalbuminaemia: a new physical sign.
      They are often most prominent on the second, third, and fourth fingernails and frequently spare the thumbnail. The underlying pathogenesis of Muehrcke's lines is incompletely understood but may be caused by vascular compression within the nail bed as the result of local edema. With pressure applied to the nail, the surrounding healthy nail will blanch, leading to a homogenous white nail until blood flow returns. Because these lines develop in response to changes in the vascular bed of the nail rather than the nail matrix itself, the lines fail to move with nail growth.
      • Wolff K.
      • Johnson R.A.
      Fitzpatrick's Color Atlas & Synopsis of Clinical Dermatology.
      • LeBlond R.F.
      • Brown D.D.
      • DeGowin R.L.
      DeGowin's Diagnostic Examination.
      Muehrcke's lines are most commonly seen in patients with chronic hypoalbuminemia (usually<2 g/dL), especially in those with nephrotic syndrome, cirrhosis, or severe malnutrition. Since Muehrcke's original discovery, Muehrcke's lines have also been described in the absence of hypoalbuminemia, most commonly in patients treated with multiple cytotoxic chemotherapy agents.
      • Wolff K.
      • Johnson R.A.
      Fitzpatrick's Color Atlas & Synopsis of Clinical Dermatology.
      • Schwartz R.A.
      • Vickerman C.E.
      Muehrcke's lines of the fingernails.
      • Bianchi L.
      • Iraci S.
      • Tomassoli M.
      • et al.
      Coexistence of apparent transverse leukonychia (Muehrcke's lines type) and longitudinal melanonychia after 5-fluorouracil/adriamycin/cyclophosphamide chemotherapy.
      Given the refractory nature of our patient's nephrotic syndrome, she later underwent another renal biopsy. This second biopsy suggested an alternative diagnosis of C1q nephropathy, a rare cause of nephrotic syndrome. Because C1q nephropathy is often resistant to corticosteroid therapy, the patient was subsequently switched to stronger immunosuppressive therapy with cyclosporine. With this new regimen, the patient's proteinuria decreased, edema resolved, and Muehrcke's lines disappeared.

      References

        • Muehrcke R.
        The finger-nails in chronic hypoalbuminaemia: a new physical sign.
        Br Med J. 1956; 1: 1327-1328
        • Wolff K.
        • Johnson R.A.
        Fitzpatrick's Color Atlas & Synopsis of Clinical Dermatology.
        Sixth Edition. McGraw-Hill Professional, New York2009
        • LeBlond R.F.
        • Brown D.D.
        • DeGowin R.L.
        DeGowin's Diagnostic Examination.
        Ninth Edition. McGraw-Hill Professional, New York2009
        • Schwartz R.A.
        • Vickerman C.E.
        Muehrcke's lines of the fingernails.
        Arch Intern Med. 1979; 139: 242
        • Bianchi L.
        • Iraci S.
        • Tomassoli M.
        • et al.
        Coexistence of apparent transverse leukonychia (Muehrcke's lines type) and longitudinal melanonychia after 5-fluorouracil/adriamycin/cyclophosphamide chemotherapy.
        Dermatology. 1992; 185: 216-217