HOW TO TREAT 29
ausdoc . com . au 11 OCTOBER 2024
HOW TO TREAT 29
Table 3 . Clinical features of different types of cutaneous warts Clinical features
Common wart ( verruca vulgaris )
• Cauliflower-like appearance with raised , rough-surfaced growths
• Grey , brown or flesh-coloured
• Often on the hands , fingers and periungual areas
Plantar wart
Flat wart ( verruca plana , also known as plane wart )
PAGE 26 or 3mm decreases the complete excision rate from 94.4 % to 87 % and 74.1 % respectively . 24
TOPICAL TREATMENT WITH 5-FLUOROURACIL CREAM The benefit of using topical treatment is that it can be applied to multiple lesions at a time and is particularly effective against thin and superficial lesions . 5-fluorouracil cream is a topical chemotherapy agent that inhibits thymidylate synthase , an enzyme essential for DNA synthesis , thus inducing apoptosis and selective destruction of abnormal cells . 23 Imiquimod 5 % cream is also another topical option . However , 5-fluorouracil has higher efficacy for Bowen ’ s disease lesions , with studies reporting clearance rates of 70-90 %. 25
Furthermore , a 2024 multi-centre randomised controlled trial with 250 patients showed that 5-fluorouracil is non-inferior to surgical excision and associated with better cosmetic outcomes . 26
CRYOTHERAPY Cryotherapy employs freezing agents such as liquid nitrogen to induce controlled tumour necrosis . It is an effective treatment option for superficial Bowen ’ s disease lesions . The main benefit is that it is relatively simple and can be performed easily in the office setting . 25 Although generally well tolerated , side effects can include pain , burning and blistering .
A fine spray of liquid nitrogen is administered at a 90-degree angle , around 1cm from the skin surface . The duration of freezing depends on the size , location and thickness of the lesion , and the individual patient ’ s tolerance . A common guideline is to freeze the lesion until a rim of frost forms around its periphery , known as an “ ice ball ”, typically taking around 5-30 seconds . 27 The ice ball may be palpated to ensure the entire lesion has been frozen . The time of total freezing depends on the size of the lesion , but for Bowen ’ s disease it ’ s generally 15-30 seconds . 28
Inform the patient about the risks , including a hypopigmented scar at the site of treatment , temporary numbness if performed over a superficial nerve and the relatively high recurrence rate of 6-21 %. 28
PHOTODYNAMIC THERAPY PDT may also be used for Bowen ’ s disease , either as monotherapy or combined with topical treatment . 29 It can be an especially useful option for those with multiple large lesions , lesions difficult to surgically resect and repair , those who have failed other therapies , or in elderly patients
• On the plantar surface of the foot
• Thick , callus-like
• May have small black dots ( thrombosed capillaries ) on the surface
• May be painful due to pressure from walking or standing
• Smooth , flat-topped
• Typically occur in clusters
• Skin-coloured , pink or light brown
• Often on the face , neck and dorsal hands
who may not be suitable surgical candidates . At 12-month follow-up , recurrence rates have been quoted to range from 0-46 %, and close long-term follow-up of lesions is recommended . 30 Practical considerations for PDT are outlined earlier .
CURETTAGE AND CAUTERY Superficial skin surgery through curettage and cautery ( C & C ) is a suitable treatment and the favoured option for solitary Bowen ’ s disease lesions on accessible areas of the body , such as the trunk , extremities and head and neck . This method involves the mechanical scraping of the lesion ( curettage ) followed by the application of electrical current to destroy remaining tumour cells ( electrocautery ). Unlike surgical excision , C & C typically results in minimal scarring , as it promotes rapid wound healing and minimal downtime for the patient . 31 However , it may result in incomplete removal of deeper or larger lesions and is dependent on the clinician ’ s technique , often leading to higher rates of recurrence compared with surgical excision . It is often a favoured choice by patients , as it is more convenient than a prolonged course of topical chemotherapy .
A practical guide for C & C is outlined in box 2 .
CUTANEOUS WARTS
CUTANEOUS warts , also known as verrucae , are among the most common dermatological conditions encountered in primary practice . Warts are benign skin growths caused by HPV , most commonly types 1 , 2 , 3 , 4 , 10 , 27 , 29 and 57 . 32 Infection with HPV occurs by direct skin contact , with increased inoculation in injured or macerated skin . Autoinoculation can also occur when a wart that is scratched results in a line or area of warts , known as pseudo-koebnerisation . 33 Infection begins in the basal epidermis and causes proliferation of keratinocytes , with an incubation period of up to 2-12 months . 32
Warts can affect individuals of all ages , although are most common in children and young adults . Risk factors for extensive or resistant warts include a defective skin barrier , such as in atopic dermatitis , and patients with impaired cell-mediated immunity , such as patients with an organ transplant , those with human immunodeficiency virus ( HIV ), or those on immunosuppressive medications . 32
Warts can appear anywhere on the body , but are most commonly found on the hands , knees , feet ( see figure 7 ) and around the fingernails ( known as periungual warts ). The
Box 1 . A practical guide for surgical excision of BCC and suspected invasive SCC
clinical features of different types of cutaneous warts are outlined in table 3 . Viral warts can also affect the mucous membranes of the genitals , perineal area or anal region , commonly known as anogenital or venereal warts . 34 However , these are caused by specific strains of HPV and are usually sexually transmitted .
Differential diagnoses
Differential diagnoses include
Figure 2 . Infiltrative BCC of the left alar groove . The patient was initially referred for Mohs micrographic surgery ; however , her background of advanced Alzheimer ’ s dementia made her an unsuitable candidate for a potentially long surgical procedure . Different treatment options were discussed and the patient eventually opted for radiotherapy .
• Preparation and marking : — The patient should be appropriately consented for the risks , benefits , alternative treatment options and any material risks .
— The lesion and surrounding skin can be cleaned with an alcohol wipe . Dermoscopic examination of the lesion while stretching the skin can help to identify its borders . Use a surgical marker to outline the BCC lesion with appropriate clinical margins ( see table 2 ).
— Examine and palpate the area around the lesion to determine the lines of skin tension ( consider Langer ’ s lines ) and choose the direction of closure , to minimise scarring . Then , mark the ellipse around the lesion , where the length is generally at least three times the width ( see figure 3 ).
• Anaesthesia : — Infiltrate the marked area with local anaesthesia . — Use a small-gauge needle to minimise discomfort . — Lignocaine 1 % with 1:100,000 adrenaline assists haemostasis and helps to minimise bleeding . — The authors prefer to leave this for 10-15 minutes prior to excision to maximise haemostasis and ensure the local anaesthetic has taken full effect .
• Excision : — Use a scalpel to incise cleanly along the marked ellipse borders . — The depth will depend on the size , type and position of the lesion . — Electrocautery may be used to achieve haemostasis .
• Closure : — The method of wound closure depends on the size and location of the lesion . — Generally , absorbable sutures can be used for deep dermal sutures and non-absorbable sutures to approximate wound edges , employing simple interrupted or running sutures as appropriate . — Tension-free closure minimises wound complications and optimises cosmetic outcomes . — Flap repairs or skin grafts may be more appropriate for larger wounds .
• Postoperative care : — Apply a surgical dressing or pressure bandage to protect the wound and assist with healing . — The authors prefer applying a breathable medical tape applied directly over the lesion , to remain in place until suture removal , and then a pressure dressing on top if required . — The wound should be kept clean and dry for 48 hours , after which the wound can be wet in the shower with the medical tape remaining in place . — Wound care instructions , advice on appropriate analgesia , and potential warning signs for infection or complications should be given to the patient . A written handout can be especially helpful .
• Pathological evaluation : — The excised specimen should be placed in formalin and submitted for histopathological examination to deduce tumour type and confirm complete removal with margins .
• Follow-up : — A follow-up appointment to monitor wound healing , remove sutures and discuss histopathology of the lesion should be scheduled for 7-14 days ( see figure 4 ). — Patients should be educated on the importance of sun protection and regular full skin examinations .
seborrheic keratosis , molluscum contagiosum , lichenoid keratosis and keratinocyte skin cancer . Plantar warts can also resemble plantar corns and callus , which are localised areas of thickened skin that develop