Approach to dysmenorrhoea in primary care.

Dysmenorrhoea is the most common gynaecological condition in women of childbearing age[ 1 ] and can be associated with significant morbidity. The prevalence of dysmenorrhoea varies from 45% to 95%, worldwide.[ 3 ] In Singapore, it was reported by 83.5% of adolescent females aged 12–19 years.[ 4 ] Dysmenorrhoea has been found to have a significant negative impact on schooling, work life and interpersonal relationships, resulting in poorer quality of life.[ 3 ] It is the main reason for repeated short periods of school and work absenteeism.[ 3 ] In Singapore, almost one in four girls reported time-off from school.[ 4 ] This is similar abroad, where 10%–30% of women who are working or studying lose 1–2 days a month due to dysmenorrhoea.[ 3 ] It has also been associated with poorer mental health, including depression and anxiety.[ 5 ] Despite the high prevalence and significant impact of dysmenorrhoea, many individuals either do not seek medical attention or undertreat with over-the-counter medications.[ 2 4 ] Adolescent patients and their caregivers may feel that pain is ’normal’ and medications are unnecessary.[ 4 ] Some reasons for this include a lack of knowledge on dysmenorrhoea and its available treatments, misconception regarding what is normal and a lack of awareness of the potential consequences of non-diagnosis and treatment.[ 4 6 ] Primary care physicians are well positioned to explore and provide evidence-based education and management for this condition, as many patients present to primary care clinics.

Patients with the following red flags should undergo prompt evaluation for secondary causes of dysmenorrhoea. Dysmenorrhoea with poor response to nonsteroidal anti-inflammatory drugs (NSAIDs) or hormonal contraception after three cycles[ 2 ] Patients in whom dysmenorrhoea started more than 2 years after the onset of menarche or who present with progressively worsening dysmenorrhoea[ 8 ] Pelvic mass or abnormal vaginal or rectal examination Symptoms suggestive of secondary dysmenorrhoea, such as abnormal uterine bleeding (menorrhagia and intermenstrual bleeding), mid-cycle or acyclic pain, deep dyspareunia, subfertility and mucopurulent vaginal discharge Family history of endometriosis or adenomyosis Renal, spine, cardiac or gastrointestinal anatomical anomalies, as these can be associated with gynaecological structural anomalies[ 8 ] Dysmenorrhoea with poor response to nonsteroidal anti-inflammatory drugs (NSAIDs) or hormonal contraception after three cycles[ 2 ] Patients in whom dysmenorrhoea started more than 2 years after the onset of menarche or who present with progressively worsening dysmenorrhoea[ 8 ] Pelvic mass or abnormal vaginal or rectal examination Symptoms suggestive of secondary dysmenorrhoea, such as abnormal uterine bleeding (menorrhagia and intermenstrual bleeding), mid-cycle or acyclic pain, deep dyspareunia, subfertility and mucopurulent vaginal discharge Family history of endometriosis or adenomyosis Renal, spine, cardiac or gastrointestinal anatomical anomalies, as these can be associated with gynaecological structural anomalies[ 8 ]

Primary dysmenorrhoea frequently begins 6–12 months after menarche, when cycles become ovulatory.[ 3 ] The pain in primary dysmenorrhoea is typically worse on the first day of the menstrual cycle and usually subsides within 2–3 days. It may radiate to the back or down the legs. Other associated symptoms include nausea, vomiting, abdominal bloating and migraine.[ 3 ] The patient with primary dysmenorrhoea will typically have normal physical examination and tend to respond to NSAIDs.

Patients with presumed primary dysmenorrhoea should be monitored for response to treatment, as this would support the diagnosis. If there is no improvement in symptoms within 3–6 months of treatment, the clinician should evaluate for treatment adherence and secondary causes of dysmenorrhoea, such as obstructive structural causes.[ 8 ] Pelvic imaging is recommended.

Secondary dysmenorrhoea usually begins a number of years after menarche.[ 3 ] It can be further subdivided into gynaecological and non-gynaecological causes [ Table 2 ]. Endometriosis and adenomyosis are the most common gynaecological causes. This is also more likely to occur in societies where childbearing is delayed and eschewed. A quick reference guide to the diagnosis and management of endometriosis can be found here: https://virtual.miceneurol.com/protocol.pdf . Non-gynaecological causes may arise from the genitourinary, gastrointestinal or musculoskeletal systems. Causes of secondary dysmenorrhoea and their characteristics.[ 1 7 ] IBD: inflammatory bowel disease, MRI: magnetic resonance imaging, STDs: sexually transmitted diseases Pelvic imaging with ultrasonography is the initial imaging modality of choice to evaluate for gynaecological causes of secondary dysmenorrhoea.[ 8 ] Transvaginal ultrasound is less influenced by body habitus and bowel shadows, and can identify pelvic pathology better than transabdominal ultrasound. However, the former is not suitable for patients with an intact hymen. Ultrasound scans done on day 2 or 3 of the menstrual cycle may avoid physiological changes that may be interpreted as pathology such as follicle development.

Dysmenorrhoea may negatively affect women's quality of life. Primary care physicians are well positioned to proactively explore the symptoms and provide appropriate education and management. In the initial evaluation of dysmenorrhoea, it is important to determine if it is primary or secondary in nature. If secondary dysmenorrhoea is suspected, the patient should be referred to a gynaecologist for further evaluation. Holistic approach of patients with dysmenorrhoea includes symptomatic treatment as well as consideration of the psychosocial issues that often accompany the disorder. NSAIDs are the recommended first-line treatment for primary dysmenorrhoea. Combined hormonal or progesterone-only contraceptives can be used in those who desire contraception. Most adolescents will have primary dysmenorrhoea. Referral to a gynaecologist should be considered if symptoms do not improve with treatment after three menstrual cycles, as these patients are more likely to be diagnosed with an organic cause. Dysmenorrhoea may negatively affect women's quality of life. Primary care physicians are well positioned to proactively explore the symptoms and provide appropriate education and management. In the initial evaluation of dysmenorrhoea, it is important to determine if it is primary or secondary in nature. If secondary dysmenorrhoea is suspected, the patient should be referred to a gynaecologist for further evaluation. Holistic approach of patients with dysmenorrhoea includes symptomatic treatment as well as consideration of the psychosocial issues that often accompany the disorder. NSAIDs are the recommended first-line treatment for primary dysmenorrhoea. Combined hormonal or progesterone-only contraceptives can be used in those who desire contraception. Most adolescents will have primary dysmenorrhoea. Referral to a gynaecologist should be considered if symptoms do not improve with treatment after three menstrual cycles, as these patients are more likely to be diagnosed with an organic cause. Closing Vignette You evaluated Ms. Lim further and found no history or risk factors suggestive of secondary dysmenorrhoea. A patient health questionnaire-2 screen for depression was negative. You prescribed her with mefenamic acid (500 mg initial dose, followed by 250 mg every 6 h) and advised her to start the tablets 1–2 days before her menstrual cycle. She asked if there was anything else she could do besides medications to improve her pain. You advised her to continue heat therapy and exercise and guided her through some relaxation techniques that can be used for self-management. You reviewed her again 2 months later, and she reported significant improvement of her menstrual pain and she had not had to miss a day of school in the past 2 months. You advised her to continue with the current treatment and to return in the event of any recurrence or worsening dysmenorrhoea. Nil. There are no conflicts of interest.

Treatment for primary dysmenorrhoea includes non-pharmacological, pharmacological and surgical methods. The patient's mood should also be explored. While there is limited high-quality evidence for non-pharmacological management of patients with primary dysmenorrhoea, several options can still be considered. These methods may also encourage self-empowerment. It is also necessary to educate the patients to equip them with medical knowledge associated with their symptoms, which may in turn improve adherence to medication and decrease pain.[ 8 ] Topical heat applied to the lower abdomen has been shown to reduce pain intensity, compared to placebo.[ 9 ] This is easily available as heat packs or heated water bottles.[ 1 ] It is thought that the topical heat activates thermoreceptors and reduces the response to nociceptors, consequently reducing pain signals to the brain. While there is limited quality evidence for exercise, it is unlikely to be harmful and can benefit physical health. Of the different exercise intensities, low-intensity exercise has been shown to have the greatest benefit in reducing dysmenorrhoea and improving overall quality of life.[ 9 ] Such exercises include yoga and stretching. There is some evidence for the use of transcutaneous electrical nerve stimulation and acupuncture in improving dysmenorrhoea. However, the trial findings are limited by small numbers.[ 7 8 10 ] Similarly, traditional Chinese medicine has also been shown to have some benefit in small studies. However, evidence evaluating the adverse effects of these medications is limited.[ 11 ] Cautionary advice should be given to patients who wish to try these options, as there is limited data regarding their efficacy and adverse effects. There may be a potential for certain supplements such as ginger, fish oil, magnesium and vitamin B1 in improving dysmenorrhoea.[ 12 ] However, the evidence is limited to small studies. Behavioural techniques such as biofeedback, as well as cognitive behavioural therapy such as relaxation training and desensitisation, may be used as adjuncts to pharmacological treatments.[ 1 ] NSAIDs are the first-line treatment and have been shown to be more effective than paracetamol.[ 13 ] They inhibit the cyclooxygenase pathway, preventing the formation of prostaglandins.[ 2 ] A Cochrane review found no superiority between the different NSAIDs; therefore, doctors are encouraged to opt for the most cost-effective option, usually ibuprofen or mefenamic acid.[ 13 ] To be most effective, patients should take NSAIDs 1–2 days before the start of the menstrual cycle. If a patient has irregular cycles and is unable to predict the start date, NSAIDs should be taken on the first day of their menstrual cycle and stopped when symptoms resolve, typically around day 2 or 3.[ 2 ] Patients can be advised to take a loading dose followed by regular dosing, as this has been shown to improve dysmenorrhoea to a greater extent compared to only a regular dose regimen [ Table 1 ].[ 2 ] NSAIDs should be taken with meals to reduce the risk of adverse gastric side effects. Avoid use of NSAIDs in patients with comorbidities such as asthma, peptic ulcer disease, cardiovascular diseases or renal impairment. Specific cyclooxygenase isoform 2 (COX-2) inhibitors may be used in those with known peptic ulcer disease. If one agent does not work, consider trying a different one.[ 8 ] Suggested nonsteroidal anti-inflammatory drugs dosing regimen for primary dysmenorrhoea.[ 2 ] Hormonal treatments that can be considered include combined hormonal contraception (CHC) and progestin-only contraceptives, including depot medroxyprogesterone acetate (DMPA), etonogestrel subdermal implant (Nexplanon ® ) and the levonorgestrel-releasing intrauterine system (Mirena ® ). Combined hormonal contraception, which includes combined oral contraceptive pill and patch, may be used as the second-line treatment in those who fail to respond or are unable to tolerate NSAIDs. However, this can be the first-line treatment for those requiring concomitant contraception. The hormones released suppress ovulation and reduce endometrial growth, thereby reducing prostaglandin secretion.[ 2 14 ] CHC has been shown to improve pain, with no difference found between the different preparations.[ 14 ] When used in continuous or extended regimens (more than 28 days of active hormone), CHC may result in improved pain control compared to the traditional cyclical regimen (21 days of active hormone with seven hormone-free days).[ 1 15 ] It is, therefore, reasonable to consider switching a patient to a continuous or extended regimen if she does not show improvement in her symptoms while on cyclical therapy.[ 15 ] Progestin-only contraceptives may provide pain relief by inducing endometrial atrophy. This option is particularly useful in patients with contraindications to the oestrogen component of CHCs, such as high body mass index (BMI) or the risk of thrombosis. There is evidence that DMPA, Nexplanon and Mirena may alleviate dysmenorrhoea.[ 1 2 ] These methods may be considered in patients who desire long-term reversible contraception, have contraindications to oestrogen or desire the convenience of long-acting treatment. Most women will experience improvement in symptoms with either non-pharmacological or pharmacological treatment. However, those who show no improvement should be referred to a gynaecologist for further evaluation. If primary dysmenorrhoea continues, the patient may be referred to a chronic pain team for a multidisciplinary approach to optimise analgesia through a biopsychosocial model. Two main surgical techniques have been reported: uterosacral nerve ablation and presacral neurectomy. While both can be performed laparoscopically, they are not common procedures. Evidence to support these approaches in the long term is limited, with adverse effects reported.[ 1 8 ] If symptoms remain refractory, patients who have completed their family or do not desire to have children may be offered hysterectomy after a successful trial of a gonadotropin-releasing hormone agonist.

Dysmenorrhoea has also been shown to be associated with psychological disorders such as depression and anxiety.[ 5 ] This relationship can be bidirectional.[ 3 ] Dysmenorrhoea may contribute to the development of psychological disorders due to the pain experienced. Conversely, patients with concomitant psychological disorders may have greater sensitivity to pain, exacerbating dysmenorrhoea. It is, therefore, important to explore the impact of dysmenorrhoea on the patient's mental well-being, with appropriate follow-up and psychologist support.