Background and Aim
Crusted scabies is a highly contagious, severe skin disease caused by hyperinfestation of the Sarcoptes scabiei mite. Transmission occurs through close skin contact with an infested person. Individuals develop thick plaques and hyperkeratosis with complications including secondary bacterial infections, typically with Streptococcus pyogenes and Staphylococcus aureus. Crusted scabies has been a notifiable condition in the Northern Territory (NT) since 2016.
Methods and Analysis
We reviewed all crusted scabies notifications in the NT from 2016 to 2025 as per NT surveillance case definitions which required microbiological confirmation for the presence of S. scabiei mites from skin scrapings and clinical evidence including visible skin abnormalities. Severity of disease was assessed using the Royal Darwin Hospital grading scale (Grade 1,2,3 in increasing severity). Variables included age, sex, Indigenous status, location, grading and hospitalisation status.
Outcomes
There were 679 notifications from 485 individuals. The median age was 50 years (range 0-90 years) with 423 (62.3%) females. Most notifications were in the Darwin region (297, 44%), followed by East Arnhem (162, 24%) and Alice Springs (89, 13%). Aboriginal people account for 650 (96%) of the 679 notifications. Most cases were Grade 1 (286, 42%) followed by, Grade 2 (243, 36%), and then Grade 3 (97, 14%); 53 (7.8%) were of unknown grading. The majority (611, 90%) were hospitalised with a median length of stay of 12 days (range 1-203 days).
There were 66 notifications (9.7%) aged under 18 years (45 individuals), with eight individuals (17.8%) having two or more notifications. The proportion of paediatric notifications increased from 3.2% in 2016 (1/31 notifications) to 20% in 2025 (19/94 notifications).
Conclusion and Future Actions
Crusted scabies is a significant cause of admissions and readmissions straining overburdened health services and compromising the lives of those affected. More targeted approaches are required to improve living conditions and scabies free environments in the NT.