DYSMENORRHEA

DYSMENORRHEA

Background

Dysmenorrhea refers to the syndrome of painful menstruation. Primary dysmenorrhea occurs in the absence of pelvic pathology, whereas secondary dysmenorrhea results from identifiable organic diseases, most typically endometriosis, uterine fibroids, uterine adenomyosis, or chronic pelvic inflammatory disease. The prevalence of dysmenorrhea is estimated to be between 45 and 95% among reproductive-aged women. Although not life threatening, dysmenorrhea can be debilitating and psychologically taxing for many women and is one of the leading causes of absenteeism from work and school.

History

Primary dysmenorrhea may be distinguished from secondary dysmenorrhea by means of a thorough history. Pertinent information includes age at menarche, abnormal vaginal bleeding or discharge, dyspareunia, and obstetric history.

Primary dysmenorrhea

Onset within 6-12 months after menarche
Lower abdominal/pelvic pain begins with onset of menses and lasts 8-72 hours
Low back pain
Medial/anterior thigh pain
Headache
Diarrhea
Nausea/vomiting

Secondary dysmenorrhea

Onset in 20s or 30s, after relatively painless menstrual cycles in the past
Infertility
Heavy menstrual flow or irregular bleeding
Dyspareunia
Vaginal discharge
Lower abdominal or pelvic pain during times other than menses
Pain unrelieved by nonsteroidal anti-inflammatory drugs (NSAIDs)
Physical
A complete physical examination should be performed. For younger adolescents who have never been sexually active, a careful abdominal examination is appropriate. In older adolescents or those known to be sexually active, a pelvic examination is crucial. Pelvic ultrasonography should be considered in women who are suspected to have secondary dysmenorrhea.
Primary dysmenorrhea
May have lower abdominal tenderness
May have uterine tenderness or normal pelvic examination (Cervical stenosis may contribute to retrograde menstrual flow.)

Secondary dysmenorrhea
Palpable uterine mass or masses
Cervical motion tenderness
Adnexal tenderness or palpable mass or masses
Vaginal or cervical discharge
Visible vaginal pathology (mucosal tears, masses, prolapse)
Normal abdominal and pelvic examinations do not rule out pathology. Ultrasonography or other imaging modalities may be warranted if suspicion of secondary dysmenorrhea is high.
Causes
Risk factors
Primary dysmenorrhea
Early age at menarche ( <12 y)
Nulliparity
Heavy or prolonged menstrual flow
Smoking
Positive family history
Obesity

Secondary dysmenorrhea
Endometriosis
Adenomyosis
Leiomyomata (fibroids)
Intrauterine device
Pelvic inflammatory disease
Endometrial carcinoma
Ovarian cysts
Congenital pelvic malformations
Cervical stenosis
Lab Studies
The diagnosis of dysmenorrhea is generally clinical.
Laboratory studies may be indicated to elucidate the cause of secondary dysmenorrhea.

Complete blood count (with differential), for evidence of infection or neoplastic process
Urinalysis, to exclude urinary tract infection
Quantitative human chorionic gonadotropin level, to exclude ectopic pregnancy
Gonococcal/chlamydial cervical swabs, to exclude STDs/PID
Stool guaiac, to rule out GI bleeding
Erythrocyte sedimentation rate (ESR), for subacute salpingitis
Emergency Department Care
As always, ED evaluation should begin with the ABCs and should consider serious diagnoses such as hemorrhagic shock and sepsis. A patient whose history and clinical presentation clearly suggest primary dysmenorrhea may be treated symptomatically and provided with appropriate follow-up. A patient whose presentation is less clear, or whose vital signs and/or physical examination are abnormal, deserves a more thorough workup, including full laboratory studies, pelvic ultrasonography, and potentially an OB/GYN consultation.
Treatment of dysmenorrhea
Treatment of dysmenorrhea is aimed at providing symptomatic relief as well as inhibiting the underlying processes that cause symptoms.
NSAIDs reduce prostaglandin production via cyclooxygenase inhibition and are used as first-line therapy for dysmenorrhea. If taken early enough and in sufficient quantity, they are extremely successful in alleviating menstrual pain. Approximately two thirds of women achieve pain relief with NSAIDs. In the ED setting, patients who do not respond to NSAIDs may require treatment with narcotics for pain control. Patients whose symptoms are not relieved by NSAIDs are very likely to have underlying pelvic pathology such as endometriosis.
COX-2 specific inhibitors have also proven effective in relieving menstrual pain. Their selectivity reduces the GI symptoms caused by inhibition of the COX-1 receptor. However, recent clinical trials have raised into question their cardiovascular safety profiles. As a result, some of these agents are no longer available.
Simple analgesics, such as aspirin and acetaminophen, may also be useful, especially when NSAIDs are contraindicated.
Oral contraceptives, which block monthly ovulation and may decrease menstrual flow, may also relieve symptoms. In one clinical trial, 65% of women reported pain relief from oral contraceptives (Proctor, 2006).
Certain dietary supplements may be effective, though their effectiveness has only been demonstrated in small clinical trials. Thiamine, pyridoxine, magnesium, and fish oil are examples (Proctor, 2006).
Drug Category: Nonsteroidal anti-inflammatory agents
These drugs are highly effective in treating dysmenorrhea, especially when they are started before the onset of menses and continued through day 2. They are readily available, relatively inexpensive, and have a low side effect profile when used cautiously and in those who have no contraindications.

Author: 
Laurel D Edmundson, MD, Clincal Assistant Instructor of Emergency Medicine, Resident, Department of Emergency Medicine, Kings County Hospital Center, Brooklyn