Management of Severe and Crusted Scabies

Severe scabies, of which crusted scabies is the most well-recognised variant, is a profuse hyperinfestation of Sarcoptes scabiei var. hominis characterised by hyperkeratotic plaques and often an absence of pruritus. Predisposition to chronic polymorbidity such as disease related or iatrogenic immunosuppression, limited mobility, sensory neuropathy, nutritional deficiency and cognitive disabilities are common in people diagnosed with severe/crusted scabies. This severe parasitic infestation is complicated by secondary infection, fluid, temperature and electrolyte dysregulation, and high morbidity and mortality are common. Due to its extremely high mite burden, it is highly contagious, and risk of the index case acting as a community core transmitter is high. Secondary community transmission is common in close personal contacts, caregivers, healthcare workers and those in contact with hyperkeratotic fomite debris. Infection of contacts leads to classic scabies with latent onset of symptoms common and contributing to further outbreaks. Early suspicion and confirmation of the diagnosis and implementation of targeted multi-modal treatments is of paramount importance. Once the diagnosis is established, surveillance and prompt management of complications as well as an implementation of strategies to rehabilitate and monitor for complications the index patient in the context of multiple contributing comorbidities can prevent morbidity and mortality. Contact tracing and prophylactic treatment regimens in contacts are required to prevent nosocomial and community outbreaks.