This supplement is published by the BDNGDermatological Nursing, 2011, Vol 10, No 2 (suppl)

Cryotherapy – IntroductionCryotherapy:the destruction of skin lesionsusing a cold substancemost commonly liquid

nitrogen LN2 (-196°C; -321°F) destruction is selective,

affecting tissue onlyinduction of an effective

immune recognition of viral or tumor cells

Cryotherapy - Indications

Treatment of:Benign lesionsPremalignant lesionsMalignant lesions

Table 1.

Some of the common conditionsresponsive to cryosurgery.

Benign lesionsViral WartsSkin tagsSeborrhoeic keratosesSebaceous hyperplasiaMolluscum contagiosumMiliaPre-malignant lesionsActinic/solar keratosesBowens disease (Intra-epithelial carcinoma)Actinic cheilitisMalignant LesionsSuperficial basal cell carcinomas

Cryotherapy - Contraindications

There are no absolute contraindications

Caution is neededwhen treating thefollowing conditions:

Table 2.Contraindications (Jackson et al, 2006)

AgammaglobulinaemiaCold intoleranceCold UrticariaConcurrent treatment with renal dialysisCollagen and autoimmune diseaseThe immunosuppressedCryoglobulinaemiaMultiple myelomaPlatelet deficiency diseasePyoderma gangrenosumRaynaud’s disease

Cryotherapy - Equipment

The equipment required depends on the method and technique used

Methods: Open spray - 40 C̊Cotton bud - 20 C̊Metal forceps - 15

C̊

Table 3.Equipment required for cryosurgery

Cryospray with a selection of nozzlesFlasksGuardsAuroscope earpieces/open conesCotton wool balls/orange sticksPlastic TeaspoonMetal forcepsDisposable scalpels (size 15)Gallipot/Styrofoam cupMagnifying glass/DermatoscopeExamination lightNon-sterile glovesApronsSharps disposal binSuitable dressingsGauze

Cryotherapy - Methods

Spray:Spot freeze most commonly used for lesion up to 2cmdiameter

If lesion is over 2cmdiameter use paint brush or rotary/spiral technique

Include rim of normal tissue

Table 4.Rim of normal skin (Andrews MD, 2004).Benign lesions1-2mm

Premalignant lesions 2-3mm

Actinic keratosis and Bowens

Do not use cryosurgery to treatlentigo maligna

Malignant lesions* 5mmSuperficial BCC

*Reminder: melanocytic lesions are not suitable for cryosurgery

Cryotherapy - Techniques

Following the freezing the lesion must thaw fully as this ispart of the cell destruction

Spray – 1cm distance from lesion

Freeze time starts from when the area is white

Once ice has developed continue for an appropriate time of 5-30 seconds intermittently

A freeze / thaw cycle is used

Cryotherapy - Procedure

Table 5.

Procedures for administration.The following procedures must be used in conjunction with local policies and procedures.

Action Rationale

General patient assessment and skin surveillance including lesion assessment

To assess suitability of both patient (age and mental capacity) and lesion for treatment

Provide verbal and written explanation of the procedure to the patient/guardian/carer and gain informed consent

To ensure the patient fully understands what the treatment involves and to elicit concordance andreduce anxiety

Assess lesion(s) for treatment and document; this could involve: measurements, photographs, body maps, diagrams

Essential for monitoring efficacy of treatment and record keeping

Hyperkeratotic lesions should be pared down prior to treatment See Appendix 2

Keratin can act as an insulator and can make the treatment less effective

Select and prepare appropriate equipmentTo ensure that treatment is delivered in a safe, effective and efficient manner

Cryotherapy - ProcedureTable 5. cont.Procedures for administration.The following procedures must be used in conjunction with local policies and procedures.

Action Rationale

Spray techniqueThis is to ensure maximum effect and best possible clinical outcome from procedure

Select appropriate nozzle according to the size of the lesion

Hold tip 1cm from the skin over the centre of the lesion

Spray gently until lesion and 1mm-5mm rim of healthy tissue becomes white (frozen)

Some patients may have low tolerance to cryosurgery and may experience extreme reactions to treatment ranging from discomfort to pain. Therefore in some cases it may be advisable to administer a test dose on the lesion

Maintain freeze with intermittent spraying for 5-30 seconds as appropriate

Allow to thaw

Repeat with second freeze as above if necessary

If indicated apply topical steroid as prescribedApplication of topical steroids may reduce post inflammatory reaction particularly in facial areas

Cryotherapy - Procedure

Only suitable for small, superficial lesions

Useful when treating young children

Table 5. cont.

Procedures for administration.The following procedures must be used in conjunction with local policies and procedures.

Action Rationale

Cotton bud techniqueThis is to ensure maximum effect and best possible clinical outcome from procedure

Prepare applicator using orange stick and cotton wool

The area of the tip of the cotton wool should be slightly smaller than the area to be treated

To ensure the applicator is tailored to the individual lesion therefore minimising trauma to healthysurrounding skin

Decant a small amount of liquid nitrogen into a non-metallic vessel such as a gallipot or a Styrofoam cup. The flask should never be usedas the reservoir due to risk of cross-contamination

A fresh cotton bud and vessel must be used for each patient, otherwise contamination will occur.Viruses such as human papilloma virus, herpes virus and hepatitis strains can remain viable attemperatures as low as -196⁰C

The cotton bud is dipped into the liquid nitrogen for a minimum of 10 secondsImmediately apply firmly and vertically to lesionContinue until whole lesion and appropriate margin is frozenRepeat as above if required to maintain an appropriate ice fieldThe liquid nitrogen should be allowed to evaporate prior to disposal of vessel

To prevent thermal injury to practitioner

Cryotherapy - ProcedureTable 5.Procedures for administration.The following procedures must be used in conjunction with local policies and procedures.Action Rationale

Forceps methodThis is to ensure maximum effect and best possible clinical outcome from procedure

Wrap gauze around the handle of the metal forceps

To prevent thermal injury to practitioner

Decant a small amount of liquid nitrogen into a non-metallic vessel such as a gallipot or a Styrofoam cup

A fresh pair of forceps and vessel must be used for each patient, otherwise contamination will occur. Viruses such as human papilloma virus, herpes virus and hepatitis strains can remain viable at temperatures as low as -196⁰C

Dip the forceps into a vessel filled with liquid nitrogen and leave until it becomes frosted (this will take approximately one minute)Grasp the lesion, including the base, and pinch until ice ball is formed and keep in place for 5-10 secondsRepeat as above if required to maintain an appropriate ice fieldFor resistant lesions this technique can be used in conjunction with the spray method to the base

If required, cover treated lesions with sterile, dry dressing

To reduce the risk of infection if skin is brokenPatient may like the area protected following treatment

Give patient written after-care advice and recommended adjunct therapies

To ensure that patients can self-manage minor expected adverse effects and how/where to seek help

Cryotherapy - Documentation

Table 5.

Documentation

Action Rationale

Document:Effects of previous treatments (if any)Lesion treatedTechnique usedNozzle size if appropriateNumber of freeze-thaw cycleLength of freeze timePatient tolerabilityAdverse eventsAfter-care instructions/adjunct therapiesA checklist may be useful. See example in Appendix 3

Records of treatment should be completed with the patient present if possible to ensureagreement. They should be clear and accurate to allow them to be interpreted by others.To standardise practice between practitioners

Cryotherapy - Indications

Table 6.

Indications for cryosurgery

Benign lesions Pre-malignant lesions Malignant lesions (under the care of specialist dermatology services)

Viral wartsSkin tagsSeborrhoeic keratosesSebaceous hyperplasiaMolluscum ContagiosumMilia

Actinic/solar keratosesBowen’s disease (Intraepithelial carcinoma)Actinic cheilitis

Superficial basal cell carcinomas

Cryotherapy - Viral WartsTable 7.

Common forms of viral warts

Clinical type Appearance

Common Firm, rough papules and nodules on any skin surface. May be single or grouped

Plane (flat) 2-4 mm in diameter, slightly elevated but most commonly flat-topped papuleswith minimal scaling

Intermediate Have features of common and plane warts

Myrmecia (verruca) Deep burrowing warts

Plantar May start as ‘sago grain-like’ papules, which develop a more typical keratoticsurface with a collar of thickened keratin

Mosaic Occur when palmer and plantar warts coalesce into larger plaques

Cryotherapy – Viral Warts

Viral warts:Infection of the epidermisHuman papilloma virus (HPV)

Treatment:Either with spray or cotton budA bud should be used on the faceTwo freeze thaw cycles are recommended

Cryotherapy – Skin Tags

Skin Tags:Common, soft, harmless lesion of collagen and blood vessels

Treatment:Forceps method or spray methodFor spray method hold tag away from skin and freeze through the base of tag

Cryotherapy – Seborrhoeic Warts

Seborrhoeic Warts:Common benign lesions often starting in adulthoodWarty, waxy, stuck on appearance

Cryotherapy – Molluscum contagiosum

Molluscum contagiosum :Small (1-5mm) lesions caused by pox virus infection of the skin

Common in :Atopic eczemaImmunocompromised patientsChildren

Treatment:Spray method

Cryotherapy – Sebaceus Hyperplasisa

Sebaceous Hyperplasisa :Enlarged sebaceous glands

Common in :Middle aged or elderly patientsImmunocompromised patientsTorré-Muir syndrome - sebaceous gland tumor

Treatment:Spray method

Cryotherapy – Millia

Millia:Tiny, superficial, keratin filled epidermal cysts

Common in :Infants and adultsCongenital or acquiredCan result from physical traumaSebaceous or sweat duct plugging

Treatment:Spray method

Cryotherapy – Actinic/Solar Keratoses

Actinic kerartosis:Hyperkeratotic lesion, chronic sun damagePink, scaly, warty or crusted lesion

Common in :Adult skinLight skinned individualsTreatment:Spray method

Cryotherapy – Bowen’s disease

Bowen’s disease:Persistent, non-elevated, red, scaly or crusted plaqueHas small potential for invasive malignancy to SSCCan grow several cm in diameter

Common in :Elderly patientsLower legsTreatment:Spray method

Actinic Cheilitis BCC

Actinic Cheilitis Superficial BBC

Cryotherapy – Side effects

PainOedema/BlisterUlcerationNerve/tendon damagePigment changeScarringInfectionUrticaria

Cryotherapy - SafetyPrecautions

Storage Liquid nitrogen should always bestored in a well ventilated room.

Personal protective equipmentWhen decanting liquid nitrogen nonabsorbent insulated gloves and a fullface visor should be worn. Opentoed shoes should not be worn

TransportationIf liquid nitrogen is to be transportedin a vehicle, the driver must be

aware of potential hazards, Especially asphyxiation, and knowwhat to do in the event of anaccident or emergency (BOC, 2004).

It should only be transported wherethe load space is separated from thedriver and passenger compartment.

Liquid nitrogen containers should be• transported in a secure upright

position• in a well-ventilated area (BOC,

2004).

Cryotherapy - Safety

COSHH regulations apply

Hazards include: Asphyxiation in poorly

ventilated areas Chronic burns Cryogenic burns / frost bite Hyperthermia

Wear protective equipment when handling

Emergency action:Inhalation: Remove individual from area Do not place yourself at risk Breathing apparatus may be

used Keep individual warm

Skin/Eye contact: Immerse affected area in

tepid 42-45°C for at least 15min and cover with dry, sterile dressing

Cryotherapy – also covers…

Medicolegal aspects

Appendix 1: Assess competency according to WASP framework

Appendix 2: Methods for removal of keratin

Appendix 3: Check list for cryotherapy

BDNGTel: 020 7681 6131www.bdng.org.uk

Dermatological Nursing, 2011, Vol 10, No 2 (suppl)