Laboratory Diagnostics of Dermatological Lesions and Disorders Flashcards
__ are indicated when the cause of a skin lesion or disease is not obvious from history and physical examination alone
diagnostic tests
oblique lighting is also known as __
side lightening
KOH stain is normally used for __
fungus
Gram stain is used for __
shape of organism
Tzank smear is used for __
herpes
oil immersion is used for __
research setting and to look at bacteria
special techniques for diagnostics
just read over these!
Magnification with a hand lens Oblique lighting Microscopy - KOH - Gram stain - Tzank Smear - Oil immersion Diascopy Dermoscopy Skin biopsy Wood's lamp Patch Test
allows you to get a closer look at enhanced morphologic detail
magnification with a hand lens
4 types of microscopy
KOH
Gram stain
Tzank Smear
Oil immersion
__ solution dropped onto a slice with a thin layer of specium sample ie scraping, discharge
KOH
2 drops of 10% to 20% KOH and let it dry for several minutes purpose is ____
dissolve the keratin of the fungal elements
__ dissolves epithelial cells to reveal hyphae, with their characteristic branching pattern, to increase the likelihood of detecting hyphae on microscopic exam of skin scraping, begin with a low light and low power
KOH
If fungal elements are not detected and clinical suspicion of tinea is high, consider arranging for a ___
fungal culture
the differentiate between gram positive and gram negative organisms, while simultaneously learning about the cellular morphology and arrangement
gram stain
___ cells have a thick peptidoglycan cell wall that is able to retain the crystal violet-iodine complex that occurs during staining
gram positive
__ cells have only a thin layer of peptidoglycan
gram negative
__ cells will appear blue - purple
gram positive
__ cells will appear pink - red
gram negative
what solution washes the violet off and allows the red stain to absorb?
ETOH solution
how long does it take for fungal cultures to come back?
weeks to months
how long does it take for bacterial cultures to come back?
24-48 hours
( SIDE NOTE: 24 hours you get a preliminary report and then at 48 hours you receive a final report. )
woods light
360-nm light source used in localizing the
site of melanin in Caucasian skin,
diagnosing infection and porphyria.
woods light is useful in
diagnosing disorders of pigmentation:
Vitiligo: completely white
Erythasma: coral red
Porphyria cutanea tarda: Dark pink urine
Pseudomonas infection of skin: pale bluegreen
Dermatophytes: yellow-green
Tinea versicolor: dull yellow
slide #33 is a case study pic w/ woods lamp
i think dr. butler said this appearance was due to just regular, NL sun exposure in everyday life
