<\/span><\/h2>\nSkin, hair<\/span> and the nail tissue is collected to microscopy<\/span> and culture<\/span> (mycology) t<\/span>or establish or confirm the diagnosis of a fungus infection<\/span>.<\/p>\nExposing the site to long wavelengths Ultraviolet radiation<\/span> (Wooden lamp<\/span>) can help identify some fungal hair infections (tinea capitis) because infected hair is fluorescent green.<\/p>\n<\/span>Collection of samples for fungal tests.<\/span><\/h2>\nSamples for microscopy and fungal culture. They are transported to the laboratory in a sterile container or in a black paper envelope. <\/span>They include:<\/p>\n\n- Scrapping of scale<\/span>, best taken from the forefront of the eruption<\/span> after cleaning the skin with alcohol<\/li>\n
- Skin stripped with masking tape, which is then affixed to a glass slide<\/li>\n
- Hair that has been pulled from the roots.<\/li>\n
- Brushed from an area climbing<\/span> on the scalp<\/li>\n
- Nail clippings or scraped skin under a nail<\/li>\n
- A skin biopsy<\/span>\n<\/li>\n
- A wet swab of a mucous membrane<\/span> surface (inside the mouth or vagina) in a special means of transport.<\/li>\n<\/ul>\n
You should also take a cotton swab pustules<\/span> in case of secondary bacterial<\/span> infection.<\/span><\/p>\n\n
\n
\n
\n<\/div><\/div><\/div><\/div>\n
<\/span>Direct microscopy of skin scrapings and nail clippings.<\/span><\/h2>\nThe material is examined by microscopy using one or more of these methods:<\/p>\n
\n- Preparation of potassium hydroxide (KOH), stained with blue or black ink<\/li>\n
- Fluorescent staining<\/li>\n
- A wet mount without smudges<\/li>\n
- A stained dry spot<\/li>\n
- \nHistopathology<\/span> biopsy with special stains, such as periodic Schiff's acid (PAS).<\/li>\n<\/ul>\n
Microscopy can identify a dermatophyte by the presence of:<\/p>\n
\n- Fungal hyphae (branched filaments) that form a mycelium<\/li>\n
- Arthrospores (broken spores)<\/li>\n
- Arthroconidia (specialized external spores)<\/li>\n
- Spores inside a hair (endothrix) or outside a hair (ectothrix).<\/li>\n<\/ul>\n
Fungal elements are sometimes difficult to find, especially if the tissue is highly inflamed, so a negative result does not rule out yeast infection.<\/p>\n
A yeast infection can be identified by the presence of:<\/p>\n
\n- Yeast cells, which can divide by budding<\/li>\n
- Pseudohyphae (branched, dermatophyte-like filaments) that form a pseudomycece.<\/li>\n<\/ul>\n\n
\n
\n
\n<\/div>\n
PAS stain from Aspergillus seen on a skin biopsy<\/p>\n
\n
\n<\/div>\n
KOH by M. canis<\/p>\n
\n
\n<\/div>\n
Candida KOH<\/p>\n<\/p><\/div>\n<\/section>\n
<\/div>\n
<\/span>Mushroom cultivation<\/span><\/h2>\nCulture identifies what organism<\/span> is responsible for the infection:<\/p>\n\n- To find out the source of infection, eg. a particular animal<\/li>\n
- To select the most suitable treatment.<\/li>\n<\/ul>\n
Cultivation of the fungus in culture can take several weeks, incubated at 25\u201330 \u00b0 C. The specimen is inoculated<\/span> in a medium such as Sabouraud's dextrose agar containing cycloheximide and chloramphenicol. Cycloheximide is left out if a template requires identification.<\/p>\nA negative culture may arise because:<\/p>\n
\n- The condition is not due to a fungal infection.<\/li>\n
- The specimen was not collected correctly.<\/li>\n
- Antifungal treatment had been used prior to sample collection.<\/li>\n
- There was a delay before the sample reached the laboratory.<\/li>\n
- Laboratory procedures were incorrect.<\/li>\n
- The organism grows very slowly.<\/li>\n<\/ul>\n
Yeast and mold culture may be due to harmless colonization rather than infection; This is common in an underlying skin condition like psoriasis.<\/p>\n\n<\/span>Cultural slopes<\/span><\/h5>\n<\/section>\n\n\n
\n
\n<\/div>\n
Non-inoculated leather scraping earrings. The blue top is Sabouraud dextrose agar with antibiotics and the white top is a dermatophyte test medium.<\/p>\n
\n
\n<\/div>\n
Morphology of the Trichophyton rubrum colony on potato dextrose agar culture plates showing reddish pigmentation at the back of the slope.<\/p>\n
\n
\n<\/div>\n
Rhodotorula grown on Sabouraud dextrose agar with antibiotics<\/p>\n<\/p><\/div>\n<\/section>\n
<\/div>\n
<\/span>Blood tests for patients with disseminated<\/span> fungal infection<\/span><\/h2>\nBlood tests are not helpful in diagnosing superficial fungal infections. In subcutaneous<\/span> and systemic<\/span> Mycosis, various tests may be helpful.<\/p>\n\n- Culture<\/li>\n
- \nAntibodies<\/span> (histoplasmosis, coccidioidomycosis)<\/li>\n
- \nAntigen<\/span> (cryptococcosis, aspergillosis, candidiasis, histoplasmosis).<\/li>\n<\/ul>\n
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\n
\n
\n<\/div><\/div><\/div><\/div>\n
<\/span>\nMolecular<\/span> biology techniques<\/span><\/h2>\nPoint-of-care tests for some yeast infections are reported to be accurate, but not yet widely available.<\/p>\n<\/section>","protected":false},"excerpt":{"rendered":"
Introducci\u00f3n Piel, cabello y el tejido de las u\u00f1as se recogen para microscop\u00eda y cultura (micolog\u00eda) to establecer o confirmar el diagn\u00f3stico de un hongo infecci\u00f3n. Exponer el sitio a…<\/p>","protected":false},"author":8,"featured_media":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"footnotes":""},"categories":[204],"tags":[],"class_list":["post-16590","wiki","type-wiki","status-publish","format-standard","category-glosario-definiciones"],"_links":{"self":[{"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/wiki\/16590","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/types\/wiki"}],"author":[{"embeddable":true,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/comments?post=16590"}],"version-history":[{"count":0,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/wiki\/16590\/revisions"}],"wp:attachment":[{"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/media?parent=16590"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/categories?post=16590"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/tags?post=16590"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}