Narrow-spectrum staining pattern of Pityrosporum.
BACKGROUND
Broad-spectrum fungal stains are used to detect fungal organisms, but narrow-spectrum stains can assist in fungal differential diagnosis. These stains include mucicarmine and Fontana-Masson (FM) for Cryptococcus, Alcian Blue for Cryptococcus and Blastomyces, Congo Red for Blastomyces and Coccidioides, and Ziehl-Neelsen for some examples of Blastomyces and Histoplasma. Pityrosporum is increasingly being recognized as a pathogen capable of significant cutaneous and systemic infections, but the narrow-spectrum staining pattern of Pityrosporum has not yet been systematically studied and reported.


METHODS
Paraffin-embedded archival tissue from 10 skin biopsies containing Pityrosporum was stained with Alcian Blue, Congo Red, Ziehl-Neelsen acid-fast stain, and FM stain. In addition to the 60-min staining time, a modified FM stain with 15-, 30-, and 45-min staining times was also performed.


RESULTS
All cases stained positive with Alcian Blue, Congo Red, and FM stains and negative with the Ziehl-Neelsen stain. The modified FM stain with the 15-min staining time showed significant staining in more than 50% of the cases.


CONCLUSIONS
The narrow-spectrum staining pattern of Pityrosporum distinguishes it from Cryptococcus, Blastomyces, Candida, Histoplasma, and Coccidioides.
Veerappan
Ranjitha
R
Department of Pathology, East Tennessee State University, Johnson City, TN, USA.
Miller
Lou Ellen
LE
Sosinski
Christina
C
Youngberg
George A
GA
D001706:Biopsy; D001758:Blastomyces; D001759:Blastomycosis / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology; D002175:Candida; D002179:Candidiasis, Cutaneous / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology; D003045:Coccidioides; D003047:Coccidioidomycosis / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology; D004396:Coloring Agents; D003453:Cryptococcosis / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology; D003454:Cryptococcus; D003881:Dermatomycoses / Q000175:diagnosis / Q000382:microbiology* / Q000473:pathology*; D003937:Diagnosis, Differential; D006651:Histocytochemistry / Q000379:methods*; D006658:Histoplasma; D006660:Histoplasmosis / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology; D006801:Humans; D008290:Malassezia; D009172:Mycology / Q000379:methods*; D012867:Skin / Q000382:microbiology* / Q000473:pathology
D004396:Coloring Agents