Impression Smear Agreement with Acetate Tape Preparation for Cytologic Sampling

Cutaneous cytologic sampling techniques are used to detect bacteria, yeast, and inflammatory cells for diagnosis and therapeutic monitoring. Studies have examined slide evaluation techniques, ear swab cytology staining methods, and observer variations; few studies compare common clinical sampling techniques. The primary aim of this study was to measure detection of microorganisms and neutrophils by impression smear compared to acetate tape preparation; comparison of agreement between two acetate tape staining methods was a secondary aim. Thirty lesions consistent with superficial pyoderma were sampled via impression smear and acetate tape preparation. Acetate tape preparations were either stained with modified Romanowksy stain solutions two and three or solution three alone. Impression smears were stained in the standard manner. Bacteria, yeast, and neutrophils were evaluated using a semi-quantitative scale [0-4]. Quantities were aggregated and compared using Cohen's kappa to measure agreement between methods. When impression smears were compared to acetate tape, the lowest agreement occurred for neutrophils, with impression smears detecting more neutrophils. Comparison of acetate tape staining methods had the highest agreement for yeast detection. Sampling technique and staining method did not differ for detection of bacteria. Impression smears detected more neutrophils, and yeast detection appeared equivalent for acetate tape staining methods.