No abstract

Background Scabies is globally ubiquitous and is a significant health issue for institutions, the economically disenfranchised, resource-poor areas, and for those with weakened immune systems. Topicals are usually effective, but are cumbersome and expensive to use in large populations and for those nonadherent to topicals. Oral ivermectin became available in Canada for the off-label treatment of scabies in the fall 2018. Objectives To review the diagnosis and management of scabies. Dose schedules and concomitant management measures are outlined for scabies simplex and for crusted scabies. Ivermectin use is outlined. Methods Medline, colleague discussions, practice review, and experience from managing scabies in institutions. Results Oral ivermectin is safe, easier to use, cheaper, more effective, and more economical than topicals in widespread institutional scabies, for those nonadherent to topicals, and in crusted scabies. Conclusions Oral ivermectin is the treatment of choice in large populations, the nonadherent, and for crusted scabies. Oral ivermectin is produced by Merck Canada as Stromectol 3 mg. The treatment dose for noncrusted scabies is 200 µg/kg, taken in a single dose with food. For example, 15 mg (5 tablets) for a 70 kg person. Retreat in 10-14 days to enhance effectiveness, and perhaps to reduce scabicide resistance.

Problems are infrequent, but patients must be informed of all material risks and treatment options. Thorough chart documentation is required, and patient consent must be given. CS doses should be as low as possible, and CS courses should be as infrequent and as short as possible. The literature reviewed in this article clearly indicates that a short course of CS of 1 week, in the absence of specific contraindications, is unlikely to be harmful (psychotic or prepsychotic episodes possibly excepted).

ILS at 2.5 mg/cc is safe, economical, and effective and its greater use should be encouraged in inflammatory dermatoses such as psoriasis and localized dermatitis. Further well-designed research would be helpful.