A study of the use of low level laser and phototherapy for the treatment of verruca pedis infections. Randomised clinical trial

Warren Turner, Assistant Dean, School of Health & Community Studies, University of Derby 

(Study Unpublished )

Background:

·         Verruca pedis is a common dermatological problem, accounting for around 9% of dermatology out-patient referrals (Keefe, 1989)
·         Lesions can be painful and affect gait of the patient (Merriman & Tollafield, 1997)
·         Existing therapies are unpredictable and largely unreliable. Success rates vary greatly between studies of effect.

Study Design:

·         Ethical committee approval obtained

·         A single blind randomised controlled trial

·         Subjects selected from referrals to Northampton School of Podiatry

·         Conducted between Oct 1995 and June 1999

 

Materials:

·         3ML Omega Laser Systems unit (London)

·         820nm single laser diode probe (200mW power output)

·         660nm single light diode probe (15mW power output)

 

  Subject Selection Criteria:

·         Inclusion criteria

·         Verruca present for >6 months

·         No previous treatment to lesion in past 12 weeks

·         Subject able to give informed consent

·         Patient available for 12 week course of visits

·         Exclusion criteria

·         Inability to meet inclusion criteria

·         Photosensitivity disorders

·         Light reactive epilepsy

·         Local CS injection to site within previous 7 days

·         Pregnant

·         Taking NSAIDs or oral steroids

·         Evidence of immuno-suppression

 

Laser Group

Placebo Group

Mean Age

20 years

20 years

Median lesion duration

12 months

12 months

Females

21

22

Males

13

7

Total Subjects

34

29

 

 

 

 

 

 

Method:

·         Subjects were randomised to receive either laser/phototherapy or placebo (dummy probes)

·         Subjects seen once per week for a maximum of 12 weeks or until lesion resolution

·         Lesions pre-operatively swabbed with Hydrex

·         Overlying callosity reduced with sharp debridement to capillary bleeding

·         Control group subjects were then exposed to a placebo ‘irradiation’ with a sham probe.

·         Study group subjects were exposed to laser/phototherapy irradiation

 

Irradiation Parameters:

·         660nm probe (visible red light)

·         20Hz pulse frequency

·         15mW probe

·         34 seconds per point, 5 points per lesion

·         4 J/cm2 total per point

·         820nm probe (infra-red light)

·         20Hz pulse frequency

·         200mW probe

·         4 Seconds per point, 5 points per lesion

·         4 J/cm2  per point

Post-Treatment Protocol:

·         Lesions dressed with Skin-tact and Mefix

·         Lesion discomfort was recorded using a 10cm VAS scale

·         Lesion resolution was determined as an absolute end point by use of a 10x magnification hand lens

·         Lesion resolution identified by normal alignment of skin striae with no sign of verruca infection

 

Results:

Rates of lesion resolution at end of 12 weeks:

·         Laser treatment group 62% resolved

·         Placebo group 17% resolved.

VAS change over 12 weeks:

·         Laser treatment group: VAS decrease 88%; No change 4%; VAS increase8%

·         Placebo group: VAS decrease 41%; No change 31%; VAS increase 28%

 

Discussion:

·         Combined low level laser and phototherapy  is significantly more effective than placebo for the eradication of verruca pedis lesions

·         Efficacy of low level laser and phototherapy is comparable to the efficacy of other therapies as reported in the literature

·         No adverse effects were reported by any of the trial subjects

·         Significant decreases in pain as measured by VAS were observed in lesions treated with laser/phototherapy compared to placebo

·         Laser/phototherapy is rarely a single treatment, lesions taking up to 12 weeks of therapy to resolve (mean = 7 weeks)

·         Mechanisms of action warrant further investigation

 

Conclusion:

·         Combined low level laser and phototherapy is a useful additional treatment for persistent verruca pedis lesions.

·         Use of laser in clinical practice may be limited owing to protracted nature of course of treatment and initial set-up costs (currently around £4,000)

·         Laser/phototherapy is free from unpleasant side-effects and is a low risk intervention 

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