Nail the Diagnosis of Half-and-Half-Nails

Your patient 

A 72-year-old male presents to you with a past medical history significant for poorly controlled diabetes mellitus type 2 complicated by diabetic nephropathy. His wife complains about a chronic change to his nails, while he doesn’t seem to mind and insists that there is nothing wrong. You note a clear delineating band appearance on the nails of all the fingers of both hands; a pink band more distal in the nail and a white, opaque band on the proximal portion of the nail bed. He denies any pain in his fingers and does not recall how long they have appeared like this. He maintains a normal diet and, despite forgetting his prescribed medications occasionally, he does maintain daily intake of a vitamin supplement.

Bottom line, upfront

Nail abnormalities can provide insight into underlying pathology and should be part of all physical exams as they are a commonly overlooked diagnostic tool. Their shape, color, and texture can help an astute clinician understand what, if any, systemic diseases may be present. In patients with half-and-half nails (also known as Lindsay’s nails), in which the proximal nail is white while the distal nail is pink or red, an underlying (chronic) renal insufficiency is the most common culprit (1)(2). The appearance is unlikely to improve with continuous renal replacement therapy (CRRT) or dialysis but has been found in some case reports to resolve after renal transplantation.

What does this mean for you as a medical provider? Your physical exam begins with the handshake.

So, what is half-and-half nail exactly? 

Half-and-half nail is a chronic condition in which the proximal nail matrix is white while the distal half is red to brown, presenting in up to one-third of dialysis patients.(3) Interestingly, there are a multitude of different nail conditions associated with renal disease alone, with published literature reporting 52%-71% of dialysis patients containing at least one nail disorder, such as Lindsay’s nails, Muehrcke’s striae, Mees’ lines, and others. (4)(5) See Table 1 below for more information.

Honestly, can we review nail anatomy? Asking for a friend.

To understand the different pathologies that present in the nail itself, we do not need to have a deep understanding of nail anatomy; however, a quick review refresher may be helpful. The main portion of the nail that we see is called the nail plate. Directly under the plate is the nail bed and the most proximal portion of the bed is the nail matrix. The skin that touches the nail plate is the eponychium and the surrounding lateral portions of the finger/toes that touch the sides of the nail plate are the lateral folds. Given that regeneration of the fingernail plate occurs over several months (and toes over 1 year), pathology noted in the nail plate suggests systemic disease that has been present in the patient over several months.

How am I going to diagnose it?

Luckily, no biopsy is required for the diagnosis—only an astute physical exam. Diagnostic labs that would be of benefit include a renal panel to evaluate for renal disease, if it has not already been diagnosed. 

How can I treat my patient for this?

As you can imagine, for Lindsay’s nails as well as the many in Table 1 that are due to underlying systemic disease, the treatment resides in the management of the underlying condition itself. With resolution of the condition, the nail pathology may or may not resolve.

That being said…

While we focused on half-and-half nails, hopefully you can see that many systemic conditions can manifest dermatologically within the nail bed. You may diagnose an underlying condition from the nail finding itself, but you are more likely to see the nail pathology secondary to the known condition that is already being treated. As a result, it is important to understand how nail findings provide a window into underlying systemic conditions that your patient may be suffering from.

References

1. Saray Y, Seçkin D, Güleç AT, Akgün S, Haberal M. Nail disorders in hemodialysis patients and renal transplant recipients: a case-control study. J Am Acad Dermatol. 2004 Feb;50(2):197–202.
2. Anees M, Butt G, Gull S, Nazeer A, Hussain I, Ibrahim M. Factors Affecting Dermatological Manifestations in Patients with End Stage Renal Disease. J Coll Physicians Surg Pak. 2018 Feb;28(2):98–102.
3. Lindsay PG. The Half-and-Half Nail. Arch Intern Med. 1967 Jun 1;119(6):583.
4. Chauhan S, D’Cruz S, Singh R, Sachdev A. Mees’ lines. The Lancet. 2008 Oct 18;372(9647):1410.
5. Martinez MAR, Gregório CL, Santos VP dos, Bérgamo RR, Filho CDSM. Nail disorders in patients with chronic renal failure undergoing hemodialysis. Anais brasileiros de dermatologia. 2010;85(3):318–23.
6. Tully AS, Trayes KP, Studdiford JS. Evaluation of Nail Abnormalities. AFP. 2012 Apr 15;85(8):779–87.
7. Singal A, Arora R. Nail as a window of systemic diseases. Indian Dermatol Online J. 2015;6(2):67–74.
8. Nail disorders and systemic disease: What the nails tell us. The Journal of Family Practice [Internet]. 2008 Aug 1 [cited 2019 May 30];57(8). Available from: https://www.mdedge.com/familymedicine/article/63260/nail-disorders-and-systemic-disease-what-nails-tell-us
9. Cutaneous manifestations of endocrine disorders: a guide for dermatologists. – PubMed – NCBI [Internet]. [cited 2019 May 30]. Available from: https://www.ncbi.nlm.nih.gov/pubmed/12688837