Clinical Notes : Video guides
1. How to perform a KOH preparation

Procedure to make 100 ml of KOH 20% w/v solution:
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Weigh 20 g potassium hydroxide (KOH) pellets.
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Transfer the chemical to a screw-cap bottle.
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Add 50 ml distilled water, and mix until the chemical is completely dissolved, add remaining distilled water and make the volume 100 ml.
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Label the bottle and mark it corrosive. Store it at room temperature. The reagent is stable for up to 2 years.
Caution: Potassium hydroxide is a highly corrosive deliquescent chemical, therefore handle it with great care and make sure the stock bottle of chemical is tightly stoppered after use.
Republic of Ireland NOTES :

This video guide is of relevance to the following :
Tinea capitis and erythema nodosum - 47
Tinea corporis and cruris - 67