Related Experiment Video
Updated: Mar 11, 2026
Deep Dermal Injection As a Model of Candida albicans Skin Infection for Histological Analyses
Published on: June 13, 2018
Correlation between histopathologic features and likelihood of identifying superficial dermatophytosis with periodic
Michael Z Wang1, Ruifeng Guo1, Julia S Lehman1,2
1Department of Dermatology, Mayo Clinic, Rochester, MN, USA.
Background:
Periodic acid Schiff-diastase (PAS-D) staining is used routinely in dermatopathology. Conventionally, parakeratosis or intracorneal neutrophils justify use of PAS-D stain to identify dermatophytosis. We aimed to investigate the histopathological features of superficial dermatophytosis.
Methods:
Skin biopsies with PAS-D stain were retrospectively reviewed by a blinded dermatopathologist. Histopathologic findings in cases with dermatophytosis were compared with those without.
Results:
We studied 110 cases, of which 63 were PAS-D positive for dermatophytes. Dermatophytes were identified on hematoxylin and eosin (H&E) staining in 49 (77.8%) of the PAS-D-positive cases. Diffuse compact orthokeratosis (79.37%, p < 0.001) and focal parakeratosis (65.08%, p = 0.03) were significantly more frequent in dermatophytosis. Intracorneal neutrophils and spongiosis were not significant findings. Fungal elements were frequently observed within compact orthokeratosis (62.0%) and parakeratosis (31.8%) but rarely within intracorneal pustules (12.7%). In some dermatophyte cases, intracorneal neutrophils (47.6%) or parakeratosis (17.5%) were absent.
Conclusions:
Compact orthokeratosis or focal parakeratosis justifies PAS-D staining, whereas the absence of intracorneal neutrophils or parakeratosis is insufficient to exclude dermatophytosis. Results indicate that having a low threshold to perform PAS-D stain is justified. PAS-D stain may be deferred until H&E slides have been evaluated.
Related Concept Videos
01:26Differential Staining Technique
01:03Fixation and Sectioning
The simplest type of preparation is the wet mount, in which the specimen is placed in a drop of liquid on the slide. A liquid specimen can be directly deposited on the slide using a dropper. Solid specimens, such as skin scraping, can be placed on the slide before adding a drop of liquid to prepare the wet mount. Sometimes the liquid is simply water, but stains are often added...