Efficacy of high doses of botulinum toxin A for treating provoked vestibulodynia.

You’d be forgiven for thinking that botox is the solution for many a woman’s psychological and physical problems.  This article explores another potential use for this drug in a condition that is notoriously difficult to treat, provoked vestibulodynia.

Provoked vestibulodynia (PV) previously known as vulval vestibulitis, is the most common clinical form of vulvodynia.  It is defined by pain in the vulval vestibule triggered by a stimulus such as wearing clothes, using tampons or of course, sexual activity.  The British Society for the Study of Vulval Diseases has produced treatment guidelines for the condition and common therapies include tricyclic antidepressants, local anaesthetic agents, physiotherapy or even vestibulectomy.  The exact aetiology of the condition is still being debated but one hypothesis is that sufferers of the condition have increased muscular hypertonia in the superficial area of the perineum, which becomes painful.  Botulinum toxin A or botox could therefore be effective in the treatment of PV by reducing muscle tone and blocking the release of neuropeptides and neurotransmitters involved in the perception of chronic pain. 

This open pilot study recruited 20 patients who attended a specialist service for vulval pathology.  The patients were aged between 18 and 60 years old with a mean age of 26.  All complained of introital dyspareunia.  Pain could be reproduced using light touch with a cotton bud on all or part of the vestibule.  All the women had undergone more conventional therapy including psychosexual therapy, for at least 3 months without response.  All had a history of vulvovaginal candidiasis but all were given an infection screen prior to treatment.  All examinations were conducted by the same doctor using EMG guidance to track the muscles.

The eligible women received 1ml of Botox injected into the right and left bulbospongiosus muscles.  The total dose given was 100U of botulinum toxin A.  Perceived vulval pain was then measured using a visual analogue scale before the injections and at 3 and 6 months after.  The ability to have sexual intercourse was also evaluated at these time points.  The subjects evaluated their sexual function using the Female Sexual Function Index and general wellbeing with the Dermatology Life Quality Index.

16 out of the 20 patients (80%) reported an improvement in the pain at 3 months which was still present at 6 months.  Before injections 18 of the patients were unable to have sexual intercourse, after 3 months 13 (72%) had been able to have sex again; 8 had no pain at all during sex, 5 had some residual pain.  The results were the same at 6 months.

Patients who responded to the injections reported improvements in sexual function and quality of life scores too.  There were no side effects reported.

This was a small pilot study but the results do look promising.  We are all aware of the psychosocial factors that can impact on vulvodynia and this study wasn’t designed to look at these factors or take them into account.  Evidence is increasingly pointing to a mixed aetiology to many sexual dysfunctions including both physical and psychological factors.  Botox may offer an additional tool in our armour to bring symptomatic relief to women with this condition while we also address any psychological processes exacerbating the condition.

 

Pelletier F, Parratte B, Penz S et al.  Efficacy of high doses of botulinum toxin A for treating provoked vestibulodynia. B J of Dermatology 2011; 164 : 617-622.

 

 

 

Filed under: MedicinePosted at 21:50

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