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

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

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.

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.

Inclusion Criteria:

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

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.