THE BURROW INK TEST FOR SCABIES

Abstract

In France, the diagnosis of scabies rests upon finding le sillon (a well defined, zigzagged burrow) on an afflicted patient with the aid of a simple fountain pen. This so called Burrow Ink Test (BIT) consists of gently rubbing the scabietic papule with the underside of a fountain pen, covering it with ink. The excess ink is then wiped off with an alcoholsaturated gauze. If a burrow is present the ink will track down it and outline the limits of the canal....

In the United States, the diagnosis of scabies is made by the direct demonstration of the mite, the egg or the scybala (fecal pellets) in the skin....

Although the importance of le sillon ... was emphasized in 1835 by Simon Francois Renucci, the BIT has been passed along from generation to generation of French dermatologists by word of mouth without ... a definitive study.... We attempted to complete the work of Dr. Renucci by comparing the BIT with the superficial shave biopsy to establish its diagnostic validity....

Results. All ... 25 BIT-positive lesions provided material for superficial shave biopsy in which the mites, eggs, fecal pellets or any combination of the three were found.... Stated another way, if a lesion was BIT positive, it was also positive with the superficial shave biopsy.

By contrast, 11 of 30 BIT-negative lesions provided material for a positive superficial shave biopsy.

Discussion. The history of scabies seems to have evolved in a "two steps forward, one and one-half steps backward" fashion.... In 1657, Hauptman observed the mite under the microscope.... Thirty years later ... Bonomo and Cestoni extracted the mite from under the skin, observed it under the microscope and described it as a "small turtle".... Unfortunately, others could not repeat this work.... Lugol (of ... solution fame) ... offered 300 crowns ... to anyone who could demonstrate the mite.