To detect the presence of eggs of Enterobius vermicularis in patients who present with nocturnal perianal pruritis or concern for pinworm infestation.
Microscope slide, clear transparent tape, tongue blade, microscope, or a cellulose-tape slide preparation.
Affix ½ inch of a 4-inch piece of tape to the underside of a microscope slide (see Fig. 25.33A).
Hold the slide against the tongue depressor 1 inch from the end and lift the long end of the tape from the slide (see Fig. 25.33B).
Loop tape over end of the depressor to expose gummed surface (see Fig. 25.33C).
Hold tape and slide firmly against the tongue depressor (see Fig. 25.33D).
Press gummed surfaces of the tape against several areas of the perianal area (see Fig. 25.33E).
Affix long portion of the tape to the slide (see Fig. 25.33F).
Smooth tape with cotton gauze (see Fig. 25.33G).
View specimen under low (×10) power.
Enterobius vermicularis. Characteristic appearance of the E vermicularis egg with contained larval form.
Cellophane Tape Preparation. Steps for obtaining the eggs of E vermicularis. See text for details. (Photo contributor: Lawrence B. Stack, MD.)
Note: Specimens are best obtained several hours after going to sleep or upon waking before a bowel movement or bath.