Scabies: a historical perspective

In this issue of the Journal, Uzun et al. nicely summarize the current knowledge on the diagnosis and management of scabies infestation. ¹ In their scoping review, the authors describe a health scourge that has plagued humans since antiquity. We can trace records of scabies infestation to biblical times, where the term zaraath (which initially referred to scaling skin but then became the origin of the word leprosy) likely referred to conditions including scabies infestation. ² This may explain how some were ‘cured’ of leprosy by bathing in the sulfur‐rich Jordan River.

We can also find records of scabies described as “lice in the flesh” in Aristotle's treatise De historia animalium. Aristotle's description of a contagious and itchy eruption caused by an organism that could be extracted from the skin with needles fits well with scabies and its scientific name, Sarcoptes scabiei var. hominis. ² Scabiei is derived from the Latin word scabere, which means to scratch and sarcoptes is from the Greek words sarx and koptein which mean “flesh cutting.” In 25 AD, the Roman author Aulus Cornelius Celsus was credited with first giving the name “scabies” to the disease and using a sulfur compound as a remedy.

During the medieval period, poets such as Dante, in his Divine Comedy (circa 1308–1321 AD), described the suffering of alchemists and forgers from scabies. In the 16th century, physician and arthropod enthusiast Dr. Thomas Moffett correctly established the pathogenic role of the scabies mite, which he described and distinguished from the louse. The 17th century produced the first drawings of the scabies mite by August Hauptmann (1607–1674 AD) and Michael Ettmüller (1644–1683 AD), shortly after the pioneering work on the microscope. It was around this time that the parasite was first extracted from the end of a burrow on human skin (Figure 1a) by Giovanni Cosim Bonomo (1663–1696 AD) and documented in his famous letter entitled, “Observations concerning the fleshworms of the human body” in 1687. Using the microscope, he was able to observe a female mite depositing an egg (Figure 1b). Bonomo noted the contagiousness of the disease and found that external remedies could control scabies, while oral treatments at the time were of no use. In 1801, the physician Joseph Adams demonstrated the transmission of disease after affixing an extracted mite to his fingers, successfully infecting himself (and, inadvertently, his family). ²

Figure 1.

(a) Several serpiginous and curvilinear burrows over the plantar foot of an infant with scabies. (b) A female scabies mite from a scraping of the end of a burrow (mineral oil mount preparation, original magnification ×100). (c) Dermoscopic image demonstrating the head of the mite at the top end of a curvilinear burrow indicated by the black arrow

Until recently, diagnosis of scabies infestation was made via skin scraping, a method similar to the procedure in the 16th century where the mite would be removed using a needle from the skin. However, in 2007, dermoscopy was shown to be a very effective tool in diagnosing scabies (Figure 1c). It has high sensitivity, even in inexperienced hands, and the accuracy of diagnosis is enhanced using UV dermoscopy. ³ While in the past, scabies was treated by manually removing the mites with a needle from the skin, the 20th century brought new treatments, such as topical permethrin, a version of natural pyrethrum found in the flowers of Tanacetum cinerariaefolium that was synthesized in the early 1970s, and oral ivermectin, a substance derived from a compound produced by microorganisms in Japanese soil in the late 1970s. Studies have demonstrated the effectiveness of individual patients and communities through mass drug administration of these agents for treating and controlling scabies. ⁴ While we have had tremendous advances in the understanding, diagnosis, and treatment of scabies, as presented in this issue, ¹ we must remain vigilant in our fight against this age‐old disease, especially in the face of reports of resistance to permethrin in humans and oral ivermectin in animals. ⁵