Importance: Crusted (Norwegian) scabies is a severe manifestation of the contagious skin infection caused by Sarcoptes scabiei. Crusted scabies has been well described in patients with known immunocompromised states. Treatment may be complicated by delayed diagnosis and/or inadequate treatment. This infection may not rank highly on one’s differential diagnosis in the absence of an immunocompromised state, highlighting the uniqueness of the case being presented. Several papers describe immunocompromised children with Down syndrome who are infected with crusted scabies. We present a case of infection in an adult with Down syndrome without evidence of an immunocompromised state.

Observations: Our patient came to us with a 13-month history of progressively worsening symptoms, the last 4-6 weeks of that time period being most dramatic, despite various treatments. We performed tissue biopsy, culture, and laboratory evaluations, which revealed numerous mites and bacterial superinfection.

Conclusions and Relevance: Crusted scabies infection may occur in adult age individuals with Down syndrome regardless of immune status, leading us to encourage practitioners to consider this condition when presented with patients of this population. We also highlight the need for further exploration of disease prevalence in this patient population.

Scabies is a highly contagious, globally prevalent, parasitic skin infestation caused by Sarcoptes scabiei var. hominis, also known as the itch mite. There have been outbreaks not only in the developing world, but also in the developed world among refugees and asylum seekers. Once infested with scabies mites, symptomatic patients, as well as asymptomatic carriers, quickly spread the disease through direct skin-to-skin contact. Typically, symptoms of scabies are characterized by an erythematous, papular, pruritic rash associated with burrows. Treatment of scabies involves using topical or systemic scabicides and treating secondary bacterial infections, if present. Given the prevalence and contagiousness of scabies, measures to prevent its spread are essential. Through application of the novel Identify-Isolate-Inform (3I) Tool, emergency medical providers can readily identify risk factors for exposure and important symptoms of the disease, thus limiting its spread through prompt scabicide therapy; isolate the patient until after treatment; and inform local public health authorities and hospital infection prevention, when appropriate. Ultimately, these three actions can aid public health in controlling the transmission of scabies cases, thus ensuring the protection of the general public from this highly contagious skin infestation.