The Half-and-Half Nail: A New Sign of Crohn's Disease? Report of Four Cases

Abstract

Systemic disease can produce changes in the nails. Perhaps the best known example of this is koilonychia as a sequale of iron deficiency anemia. "Half and half nail" is a type of pseudoleuconychia that can be caused by chronic renal disease, Kawasaki's disease, cirrhosis, and zinc deficiency. It has not been described in patients with Crohn's disease yet. Four male patients with Crohn's disease were observed. None of them had extraintestinal manifestations of Crohn's disease. The average duration of the disease was 5.25 (range, 1-10) years. The nail alterations were defined with a portion of the nail being as much as 15 to 40 percent of normal color distally, whereas the rest of the nail was white. The contrast between the two zones remains sharply demarcated even after constricting venous return. Histologic examination was not performed. Every patient had zinc deficiency but not hypalbuminaemia or sideropenia. After review of relevant literature (MEDLINE, PubMed, etc.), we found that half-and-half nail had not been described in Crohn's disease. This study was designed to highlight the fact that the half-and-half nail, which was thought to be a sign of chronic renal failure, also occurs in patients with Crohn's disease. The relationship of this symptom to clinical activity cannot yet be assessed and has only been observed in four cases.

Nail changes in chronic renal failure patients under haemodialysis

“…On the other hand, half‐and‐half nail is seen in other conditions as Kawasaki's disease, liver cirrhosis, zinc deficiency, and Crohn's disease and also reported in a case of pellagra. Sometimes, no definite relation could be find with a particular disease 18 …”

Nail dyschromias

“…[10] Chemotherapy, zinc deficiency, liver cirrhosis, Kawasaki disease and recently described reports with Crohn's disease are the other causes of half and half nails. [11,12] b. Terry's nail: This is seen commonly in patients with cirrhosis where a large part of the nail is opaque white, obscuring the lunula, leaving only a thin band of pink -brown distal nail [ Figure 2]. This can also be present in patients with congestive heart failure, diabetes mellitus and old age.…”

Evaluation of nail lines: Color and shape hold clues

“…[21][22][23] Half-and-half nails have been reported with Kawasaki disease, hepatic cirrhosis, Crohn disease, zinc defi ciency, chemotherapy, Behçet disease, and pellagra. 3,24,25 They should be distinguished from Terry nails, which are characterized by leukonychia involving more than 80% of the total nail length. 26 Black-brown vertical lines may represent nail trauma, infection, endocrine disorders, melanoma, or benign nevi…”