Evidence for an Immunologic Cell-Mediated Mechanism

chronic renal failure and rarely in patients receiving cytotoxic therapy. The pigmentation in this condition, unlike that in the “harlequin n�.ii:’ appears to be located in the nail bed rather than the nail plate and hence does not grow out with the nail.� In this era of increasingly complex diagnostic technology and therapeutic intervention, there continues to be interest and a growing literature on bedside diagnosis.’#{176} The “harlequin nail” is a simple clinical sign that provides useful information on the patient and that underscores the rewards ofcareful bedside examination.