How is a skin scraping taken to diagnose a subcutaneous tick? - briefly
Using sterile forceps, the clinician lifts a small area of skin over the suspected lesion, applies a drop of mineral oil, and gently scrapes with a sterile scalpel blade to collect superficial tissue and any attached tick parts. The specimen is transferred to a glass slide, covered with a cover slip, and examined microscopically for tick morphology.
How is a skin scraping taken to diagnose a subcutaneous tick? - in detail
A skin scraping intended to confirm a subcutaneous tick follows a precise, sterile protocol.
First, the patient lies supine or in a comfortable position that exposes the suspected area. The region is examined visually and with a magnifying lens to locate any palpable nodule, erythema, or track marks. The skin surface is cleaned with 70 % isopropyl alcohol, allowing it to dry before any instrument contacts the tissue.
A sterile, single‑use scalpel blade (size 15 or 20) or a curette is selected. The clinician holds the blade at a shallow angle, grips the skin firmly with gloved fingers, and applies gentle pressure to lift a thin layer of epidermis. The blade is moved in a back‑and‑forth motion, scraping a 2–3 mm square area. The goal is to collect enough keratinous material to include any embedded arthropod parts without causing deep bleeding.
The collected debris is transferred immediately onto a glass slide using a sterile spatula or the blade edge. A drop of 10 % potassium hydroxide (KOH) solution is added to dissolve keratin and clear the sample. The slide is covered with a cover slip, sealed with nail varnish, and labeled with patient identifiers, date, and anatomical site.
Microscopic examination proceeds within 15–30 minutes. Under low power (10×) the technician screens for tick mouthparts, legs, or hemoglobinized tissue. High power (40×) confirms species by examining the scutum, anal groove, and spiracular plates. If no tick structures appear, the sample may be re‑stained with Giemsa or examined with fluorescence microscopy for residual DNA.
Throughout the procedure, universal precautions are observed: gloves, eye protection, and proper disposal of sharps in a puncture‑proof container. Documentation includes the scraping technique, any observed tick remnants, and the final diagnosis. This systematic approach maximizes diagnostic yield while minimizing patient discomfort and infection risk.