Burrow Ink Test for Scabies
A 20-year-old man presented to the dermatology clinic with a 3-month history of generalized itchiness. A sexual partner of the patient had similar pruritus. On physical examination, multiple erythematous papules were seen on the trunk, in the genital area, and on the flexor aspects of the wrists (Panel A). There were no visible skin burrows. However, when a papule on the wrist was covered with a purple skin marker (Panel B) and then wiped with an alcohol swab, an ink-filled skin burrow became visible (Panel C). On the basis of this positive “burrow ink test,” a diagnosis of scabies was made. Scabies is a pruritic skin infestation caused by Sarcoptes scabiei var. hominis, the only mite known to burrow into the stratum corneum. The burrow ink test is a simple, rapid, and inexpensive method to visualize the pathognomonic burrows. A negative test does not rule out scabies, however, and further testing with dermoscopy or microscopic examination of skin scrapings is necessary. Treatment with both ivermectin and topical permethrin was given owing to the severity of the patient’s symptoms. The patient’s close contacts were also notified of the diagnosis and treated. Four weeks after the initial presentation, the patient’s symptoms had completely abated.