Sensitivity of Self-collected Skin Sampling for Scabies: a Pilot Study

Early Phase 1

Recruiting

• Conditions: Scabies
• Interventions: Diagnostic Test: Skin sampling

• Registration Number: NCT06546579
• Lead Sponsor: Radboud University Medical Center

Brief Summary

In this cross-sectional diagnostic study, healthy adults aged 18 and older with suspected, clinical, or confirmed scabies will be recruited. The objective is to determine if the sensitivity of self-collected skin samples for scabies diagnosis is non-inferior to professional sampling, and compare the sensitivity and specificity of the polymerase chain reaction assay (PCR) versus microscopy.

Detailed Description

Scabies infestations have significantly increased globally in the last 10-20 years, including a threefold rise in the Netherlands over the past decade. Diagnosing scabies is challenging due to varied symptoms and low sensitivity of current microscopic methods. New diagnostic techniques like PCR, which offer higher sensitivity, are being investigated. The feasibility of self-collected skin samples is being explored to reduce the burden on healthcare services and address issues like autonomy, stigma, and privacy.

In this cross-sectional diagnostic study, healthy adults aged 18 and older with suspected, clinical, or confirmed scabies will be included. Primary endpoint is the sensitivity of self-collected versus professional skin samples for diagnosing scabies. Secondary endpoints include sensitivity of skin scrapings and swabs, and the sensitivity and specificity of PCR versus microscopy.

Participants will self-collect skin samples during a standard care visit. The process may be slightly sensitive but not painful. There are no direct benefits beyond standard care.

Study Timeline

• Status Verified: 2024-07
• Study First Submitted: 2024-07-26
• Study First Submitted QC: 2024-08-06
• Last Update Submitted: 2024-08-06
• Study First Posted: 2024-08-09
• Last Update Posted: 2024-08-09
• Study Start: 2024-08-21
• Primary Completion: 2025-06
• Study Completion: 2025-06

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 144

Inclusion Criteria

• 18 years or older
• Have either suspected scabies, clinical scabies or confirmed scabies (see table 1)
• Providing informed consent (IC)

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Exclusion Criteria

• Individuals not speaking or understanding the Dutch or English language.
• Individuals who have been diagnosed with scabies in the last six weeks and had started treatment.
• Individuals who have used ivermectin for other diagnoses than scabies in the last six weeks.
• Individuals younger than 18 years.
• Individuals with immunosuppressive conditions (see appendix A).
• Any other condition, finding or situation which, in the opinion of the investigator, may significantly increase the risk to the individual because of participation in the study, affect the ability of the individual to participate in the study or impair interpretation of the study data.

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Experimental group	Skin sampling	All participants will be asked to perform self-sampling and irrespective of the result will receive current standard-of-care from their health care provider for their suspected scabies.

Primary Outcome Measures

Name	Time	Method
The sensitivity of professionally-collected skin samples for diagnosing scabies	through study completion, an average of one year	The proportion of professionally-collected samples collected at the enrolment visit that are tested positive, divided by the total number of participants adjudged retrospectively to have had scabies at their enrolment visit, based on a composite clinical diagnosis.
The sensitivity of self-collected skin samples for diagnosing scabies	through study completion, an average of one year	The proportion of self-collected samples collected at the enrolment visit that are tested positive, divided by the total number of participants adjudged retrospectively to have had scabies at their enrolment visit, based on a composite clinical diagnosis.

Secondary Outcome Measures

Name	Time	Method
The sensitivity of skin swabs for diagnosing scabies	through study completion, an average of one year	The proportion of skin swabs at their enrolment visit (whether professionally or self-collected) that are tested positive by PCR, divided by the total number of participants adjudged retrospectively to have had scabies at baseline, based on a composite clinical diagnosis.
The sensitivity of skin scrapings for diagnosing scabies	through study completion, an average of one year	The proportion of skin scrapings at their enrolment visit (whether professionally or self-collected) that are tested positive by PCR, divided by the total number of participants adjudged retrospectively to have had scabies at baseline, based on a composite clinical diagnosis.
The sensitivity and specificity of PCR on skin scraping for diagnosing active scabies infection	through study completion	The proportion of participants adjudged to have had scabies at their enrolment visit (based on a retrospective composite clinical diagnosis), whose skin scraping at their enrolment visit (whether professionally or self-collected) are tested positive for scabies by PCR, and the proportion of participants adjudged retrospectively to have not had scabies at their enrolment visit whose skin scrapings are tested negative for scabies by PCR.
The sensitivity and specificity of microscopy on skin scraping for diagnosing active scabies infection	through study completion, an average of one year	The proportion of participants adjudged to have had scabies at their enrolment visit (based on a retrospective composite clinical diagnosis), whose skin scraping at their enrolment visit (whether professionally or self-collected) are tested positive for scabies by microscopy, and the proportion of participants adjudged retrospectively to have not had scabies at their enrolment visit whose skin scrapings are tested negative\* for scabies by microscopy.

Trial Locations

Locations (1)

Radboudumc; 🇳🇱 Nijmegen, Gelderland, Netherlands