Scabies Referrals to a New Zealand Dermatology Service: Recognition, Treatment and Persistent Symptoms

Scabies remains an important public health issue in New Zealand, particularly amongst socioeconomically disadvantaged populations. This study evaluated scabies-related referrals to a regional dermatology service, including treatment patterns, symptom persistence, and equity outcomes.

A retrospective observational study was conducted of scabies-related referrals submitted to Waikato Dermatology between July 2024 and June 2025. Data was accessed through the Best Practice Advocacy Centre (BPAC) New Zealand database, with reference to clinical records and the New Zealand ePrescription Service (NZePS). Demographic characteristics, referral patterns, treatment before and after dermatology review, and persistent symptoms were reviewed. Diagnoses were categorised as dermatologist-diagnosed or possible scabies, based on specialist clinical assessment with reference to the International Alliance for the Control of Scabies (IACS) diagnostic criteria.

Over the 13-month period, 149 referrals were reviewed, of which 117 (78.5%) were dermatologist-confirmed or possible scabies. The median age was 30 years, and 35% identified as Māori. Referrers explicitly suspected scabies in 89 referrals (76.1%), while burrows were documented in only 18 referrals (15.4%). Following dermatology review, combined permethrin and ivermectin prescribing increased significantly, from 14 (12.0%) to 46 patients (39.3%) (McNemar p < 0.001). Persistent symptoms were reported in 63 patients (53.8%) and were significantly more common in dermatologist-diagnosed scabies than in possible scabies (odds ratio 6.0, 95% confidence interval (CI) 2.2-16.4; p < 0.001). Symptom persistence was significantly more common in Māori patients than New Zealand European patients (75.6% vs. 47.3%; odds ratio 3.5, 95% CI 1.4-84; p < 0.001).

Most scabies-related referrals were clinically consistent with dermatologist-diagnosed or possible scabies, and clinical recognition by referrers was generally high, although classical supporting features were inconsistently documented. Persistent symptoms were common and likely multifactorial, more in keeping with treatment complexity, reinfestation, and socioeconomic barriers than true antiparasitic resistance.