To the Editor.—In an excellent review of mucocutaneous lymph node syndrome (MLNS) by Yanagihara and Todd (Journal 1980;134:603-614) and more recently in a case report by Glanzer et at,1 transverse grooves or furrows are described, which appeared one to two months after the illness. The former report states that the grooves are in the "nail bed."
First, the groove is actually in the fingernail, or less commonly the toenail, per se, not the bed.2 It is a result of matrix arrest during an intense physiological insult. The degree of arrest dictates how deep the groove is to be, even perhaps allowing nail shedding.
Second, the nature of the finding is totally nonspecific for MLNS. It is found as a result of physiologic stresses as varied as childbirth (mother and child), bullous pemphigoid, or typhoid fever, and was originally described by Beau in 1846.3 Maybe in this