KOH

KOH

Symbol for potassium hydroxide.

KOH

chemical formula for potassium hydroxide.

KOH

Abbreviation for potassium hydroxide.

KOH

The chemical formula for potassium hydroxide, which is used to perform the KOH test. The tests is also called a potassium hydroxide preparation.

Mentioned in: KOH Test

potassium hydroxide

; KOH topical, strongly alkaline, caustic and keratolytic chemical, liberating hydroxyl (OH^-) ions on dissolution in sweat; OH^- ions react with and break down side salt linkages of keratin molecules; formulated as 85% pellets; used to achieve local destruction of tissue (e.g. nail matrix) or lesions (e.g. verrucae); see Table 1

Table 1: Caustic agents used in podiatric practice to achieve local tissue destruction

Agent	Action	Special precautions	Contraindications
Monochloroacetic acid (crystals or saturated solution) e.g. single VP	Keratolytic; hydrolysing agent Non-self-limiting	Deep penetration Painful Do not use mask if applying solution Use a mask if applying crystals Review in 5-7 days Neutralize with foot bath ± NaHCO3 or NaCl	Soft-tissue atrophy Peripheral vascular disease Sensory neuropathy
Salicylic acid paste (40-70%) e.g. single VP; plantar hard corn	Keratolytic; hydrolysing agent	Macerates tissues Review in 7-14 days May be used in conjunction with monochloroacetic acid crystals Neutralize with foot bath ± NaHCO3 or NaCl	Soft-tissue atrophy Peripheral vascular disease Sensory neuropathy
Pyrogallic acid e.g. single VP	Keratolytic; oxidizing agent	Deep penetration Review in 3-5 days Prolonged caustic action Do not apply more than 3 times sequentially Stains skin black/brown	Use with great care: may cause deep tissue breakdown Soft-tissue atrophy Peripheral vascular disease Sensory neuropathy
Trichloroacetic acid (saturated solution; 10% solution) e.g. mosaic VP	Mild keratolytic Protein precipitant	Shallow penetration Neutralize with foot bath ± NaHCO3 or NaCl Review in 3 weeks	Peripheral vascular disease Sensory neuropathy
Silver nitrate (70% solution; 75-95% stick) e.g. mosaic VP; as a protective skin application below a mask	Protein precipitant Self-limiting Stains skin black/brown Maximum effect occurs within 24 hours	Some patients show hypersensitivity to silver nitrate (or experience acute pain) Neutralize with NaCl foot bath May be applied in alternate layers with trichloroacetic acid	Peripheral vascular disease Known sensitivity
Potassium hydroxide (KOH; 85% pellets)	Strong keratolytic	Potentially deep penetration Action of KOH stopped by application of 5% acetic acid after macerated coagulum has been removed Single treatment	Soft-tissue atrophy Peripheral vascular disease Sensory neuropathy
Phenol (80% solution or 100% crystal)	Protein precipitate	Action retarded by flooding with industrial methylated spirit Skin overspill flooded with glycerine Review as per postoperative protocol	Peripheral vascular disease (phenol suppresses inflammatory response)
VP, verruca pedis.

KOH

potassium hydroxide.