Vulvodynia

Vulvodynia is chronic vulvar pain of at least 3 months' duration without an identifiable cause, with potentially associated factors. It affects about 8 to 16% of women at some point in life, with peak onset at 18 to 25 and 35 to 44 years. It is classified by location (localised, generalised, mixed), provocation (provoked, spontaneous, mixed), onset (primary, secondary) and temporal pattern (intermittent, persistent, constant). Provoked vestibulodynia (localised, provoked pain at the vestibule) is the commonest form.

Pathogenesis is multifactorial: peripheral nerve proliferation and sensitisation (increased density of nociceptive fibres in the vestibule), neuroinflammation, mast cell activation, hormonal factors (hormonal contraceptive use, low oestrogen with low androgen effect on vestibular tissue), pelvic floor muscle hypertonicity, central sensitisation, genetic polymorphisms (IL-1 receptor antagonist), recurrent candidiasis, and psychosocial factors (catastrophising, anxiety, past trauma). It is a diagnosis of exclusion.

• Burning, stinging, rawness, irritation or knife like pain at the vulva, often with dyspareunia, tampon intolerance, pain with sitting, cycling, tight clothing or gynaecological examination
• Provoked vestibulodynia: pain on touch or pressure at the vestibule (introital dyspareunia)
• Generalised vulvodynia: constant burning, may include pudendal nerve territory
• Normal or mildly erythematous vestibule; pain on light touch with a moistened cotton swab ("Q-tip test") at 2, 4, 6, 8 and 10 o'clock positions (rated 0 to 10)
• Hypertonic, tender pelvic floor muscles (levator ani, obturator internus)
• Comorbid conditions: interstitial cystitis or painful bladder syndrome, irritable bowel syndrome, fibromyalgia, chronic fatigue, temporomandibular disorders, anxiety and depression

• History: onset, location, triggers, associated symptoms, prior treatments, sexual function, and psychosocial assessment
• Examination: inspect vulva for dermatoses (lichen sclerosus, lichen planus, eczema), infection (candidiasis), atrophy, and fissures; cotton swab test; assess pelvic floor muscle tone; speculum examination if tolerated
• Exclusion of other causes: wet mount, vaginal pH and fungal culture (including non-albicans Candida), HSV PCR, bacterial vaginosis and trichomonas testing, biopsy of suspicious skin lesions, assessment of neuropathic pain (pudendal neuralgia, sacral radiculopathy), hormonal status (hypo oestrogenism), and contact dermatitis review
• Validated tools: Female Sexual Function Index, pain questionnaires

Treatment is multimodal, stepwise and individualised.

• Education, reassurance, and vulvar care: avoid irritants (scented soaps, wipes, douches), use cotton underwear, gentle cleansing with water, lubricants (silicone based or oil based) for intercourse, cold gel packs, and avoidance of contributing activities.
• Topical agents: lidocaine 5% ointment applied to the vestibule 20 to 30 minutes before intercourse, or overnight (nightly application for 6 to 8 weeks); compounded topical amitriptyline 2% with baclofen 2% cream, gabapentin 6% cream; oestradiol 0.01% cream or testosterone 0.025 to 0.05% for hormonally mediated vestibulodynia; avoid topical steroids unless dermatosis is present.
• Oral neuromodulators for generalised or neuropathic pain: amitriptyline 10 mg at night increasing by 10 mg weekly to 50 to 100 mg; nortriptyline; duloxetine 30 to 60 mg daily; gabapentin 300 mg at night titrated to 1,200 to 3,600 mg/day in divided doses; pregabalin 75 to 300 mg twice daily.
• Pelvic floor physical therapy (the first line physical therapy, 8 to 12 sessions: manual therapy, biofeedback, dilators, relaxation techniques), with vaginal dilators for secondary vaginismus.
• Cognitive behavioural therapy, sex therapy, mindfulness, and couples therapy.
• Botulinum toxin A 50 to 100 units into the pelvic floor muscles for refractory hypertonicity (evidence mixed); nerve blocks (pudendal block with bupivacaine and triamcinolone); intralesional injection (interferon, triamcinolone, local anaesthetic).
• Surgery: vestibulectomy (excision of the painful vestibular tissue, with a success rate of 60 to 90% in carefully selected women with provoked vestibulodynia after conservative treatment fails).
• Acupuncture and transcutaneous electrical nerve stimulation: adjuncts.
• Follow up at 6 to 12 weeks; expectation setting (improvement is gradual; recovery in up to half of women over months to years).