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1. a caustic substance or hot or cold instrument used in cauterization.
chemical cautery chemocautery.
cold cautery cryocautery.
electric cautery electrocautery (def. 2).
Any substance that destroys tissue on application.
chemical cauterytopical application of strong caustics to destroy skin cells or neoplasms, e.g. verrucae; the stronger the caustic, the greater the degree of tissue destruction caused; cauterizing chemicals include monochloroacetic acid, pyrogallic acid, potassium hydroxide, 40–70% salicylic acid, >25% silver nitrate (Table 1)
|Lesion site||Superficial lesion, non-weight-bearing skin – use liquid caustics|
20% salicylic acid in collodion
Trichloroacetic acid, saturated solution (+75% sliver nitrate)
Deeper lesion, weight-bearing skin, good fibrofatty padding – either liquid or solid caustics
Monochloroacetic acid, saturated solution
40–70% salicylic acid ointment
|Number and size of lesions||Large lesions: ointment-based caustics|
40–70% salicylic acid ointment Smaller and satellite lesions: caustic solutions
Alternating layers of trichloroacetic acid, saturated solution and 75% silver nitrate
|Skin texture||Sweaty or hyperhidrotic skin|
Padding cannot be retained in situ
Fair skin or atopic individuals; atrophic or dry skin
Tend to overreact/undergo tissue breakdown, to applied caustics
|Circulation||Reduced arterial supply (diabetes, atherosclerosis)|
Caustics may cause ulceration or predispose to infection as healing response is depressed (use astringents or mild keratolytics)
Impaired venous or lymphatic drainage (oedematous tissues)
Avoid strong caustics (use astringent agents or mild keratolytics)
|Neuropathy||Impaired pain awareness (as in diabetic neuropathy)|
Do not use caustics (use astringents or mild keratolytics)
|Availability||Strong acids should not be used unless both practitioner and patient are available for emergency appointments|
Caustics may not be treatment of choice if patient cannot return weekly for ongoing treatments (consider a ‘one-off’ treatment, e.g. cryotherapy)
Opt for self-applied milder, topical ongoing treatments, if in patient's best interests
|Age||Strong caustics should be avoided in young patients with a low pain threshold|
Caustics that require padding to be retained in situ between treatments may be contraindicated in patients who cannot keep foot dry (e.g. swimmers)
|Previous treatments||It is pointless continuing with a treatment that has already proved to be ineffective, or has caused an adverse reaction|
|Single treatments||Verrucae pedis do not often respond to a single treatment, but methods include:|
• Cryotherapy (application of liquid nitrogen, optimally every 3 weeks; ice ball must extend beyond lesion edge; contraindicated in patients with peripheral vascular disease)
• Electrosurgery (peripheral tissues must also be removed in order to clear all virally infected cells; requires local anaesthesia; contraindicated in patients with peripheral vascular disease or those with an indwelling pacemaker)
|Alternative treatments||Alternative treatments may be indicated for cases that have not responded to other forms of treatment: many of these therapies have not been tested by formal research|
Thuja tincture: painted on lesion once or twice a day
Kalanchoe leaves: fleshy leaves split open and fleshy pulp left in situ on lesion; changed every 24–48 hours
Tea tree oil: painted on lesion daily, and covered
Banana skin: small piece of banana skin cut to size of lesion and strapped in place, pith side against lesion; changed every 24–48 hours