1. Primary Dysmenorrhea

Primary dysmenorrhea is menstrual pain associated with ovular cycles in the absence of pathologic findings. The pain usually begins within 1-2 years after the menarche and may become more severe with time. The frequency of cases increases up to age 20 and then decreases with age and markedly with parity. Fifty to 75 percent of women are affected at some time, and 5-6% have incapacitating pain.

Primary dysmenorrhea is low, midline, wave-like, cramping pelvic pain often radiating to the back or inner thighs. Cramps may last for 1 or more days and may be associated with nausea, diarrhea, headache, and flushing. The pain is produced by uterine vasoconstriction, anoxia, and sustained contractions mediated by prostaglandins.

Clinical Findings
The pelvic examination is normal between menses; examination during menses may produce discomfort, but there are no pathologic findings.

Nonsteroidal anti-inflammatory drugs (ibuprofen, ketoprofen, mefenamic acid, naproxen) are generally helpful. Drugs should be started at the onset of bleeding to avoid inadvertent drug use during early pregnancy. Medication should be continued on a regular basis for 2-3 days. Ovulation can be suppressed and dysmenorrhea usually prevented by oral contraceptives.

Proctor M et al: Dysmenorrhea. Clin Evid 2002;7:1639.

2. Secondary Dysmenorrhea

Secondary dysmenorrhea is menstrual pain for which an organic cause exists. It usually begins well after menarche, sometimes even as late as the third or fourth decade of life.

Clinical Findings
The history and physical examination commonly suggest endometriosis or pelvic inflammatory disease. Other causes may be submucous myoma, IUD use, cervical stenosis with obstruction, or blind uterine horn (rare).

Laparoscopy is often needed to differentiate endometriosis from pelvic inflammatory disease. Submucous myomas can be detected most reliably by MRI but also by hysterogram, by hysteroscopy, or by passing a sound or curette over the uterine cavity during D&C. Cervical stenosis may result from induced abortion, creating crampy pain at the time of expected menses with no blood flow; this is easily cured by passing a sound into the uterine cavity after administering a paracervical block.

A. Specific Measures

Periodic use of analgesics, including the nonsteroidal anti-inflammatory drugs given for primary dysmenorrhea, may be beneficial, and oral contraceptives may give relief, particularly in endometriosis. Danazol and GnRH agonists are effective in the treatment of endometriosis (see below).

B. Surgical Measures
If disability is marked or prolonged, laparoscopy or exploratory laparotomy is usually warranted. Definitive surgery depends upon the degree of disability and the findings at operation.

Proctor M et al: Dysmenorrhea. Clin Evid 2002;7:1639.

Provided by ArmMed Media
Revision date: July 9, 2011
Last revised: by Jorge P. Ribeiro, MD