Pelvic inflammatory disease (or PID) represents a polymicrobial infection usually occurring in sexually active females when causative microorganisms ascend from the lower into the upper genital tract. The severity of clinical manifestations may vary, with a majority of patients presenting with a rather mild disease. The adequate diagnosis is often delayed due to nonspecific presentation – hence there is always a need for clinical suspicion.

Common symptoms of pelvic inflammatory disease

The most commonly observed symptom of acute PID is abdominal pain that is bilateral and restricted to the lower abdomen. It is severe in the acute stages, accompanied with a high temperature, and spreads upwards if general peritonitis ensues. Vomiting may also be a sign, and the patient may develop profuse and prolonged uterine bleeding.

The patient usually presents with tachycardia, while the tongue indicates signs of dehydration. Abdominal examination reveals distension combined with rigidity and tenderness in the lower parts of the abdomen.

In later stages, after the tenderness lessens following therapy, a fixed sensitive mass arising from the pelvis is often palpable.

The affected women may also suffer from dyspareunia (i.e. recurrent or persistent genital pain during or after sexual intercourse), backache and infertility. The uterus is often in retroverted position with restricted mobility, with a possible thickening of the appendages which are, again, painful on palpation.

Short-term complications of PID may include periappendicitis and perihepatitis (also known as Fitz-Hugh-Curtis syndrome). Whilst the pathogenesis of the latter condition is not completely elucidated, up to 15 percent of patients who present with PID will experience this complication. Accompanying symptoms are mild or severe abdominal pain (most notably in the right upper quadrant), enlargement of the liver, and tenderness to abdominal palpation.

Differences according to the putative microorganism

There are also certain differences regarding the implicated microorganism. While PID caused by Neisseria gonorrhoeae is associated with symptoms that last three days or fewer, chlamydial PID usually presents with symptoms that last more than seven days. Non-gonococcal and non-chlamydial PID present as similar to gonococcal disease.

A body temperature higher than 38 °C, mucopurulent cervicitis and palpable adnexal masses are also signs that are more commonly observed when Neisseria gonorrhoeae is a primary factor in causing PID. In contrast, Chlamydia trachomatis is more likely to cause abnormal uterine bleeding and an elevated erythrocyte sedimentation rate (ESR).

In the PEACH trial (an acronym for PID Evaluation and Clinical Health trial), women with PID primarily caused by Chlamydia trachomatis or Mycoplasma genitalium presented to the gynecologist or their attending physician. This was compared with women that had gonorrhea-associated PID, suggesting an altogether milder clinical course for this disease.

Clinical evaluation and differential diagnosis

Generally, the clinical presentation of PID can be quite variable; therefore a high index of suspicion is warranted. In practice, when a woman of a generative age presents with pelvic or lower abdominal pain, PID must be taken into account in the differential diagnosis. Other potential diagnoses are ectopic gestation, intrapelvic bleeding, ovarian torsion, acute appendicitis, endometriosis, diverticulitis, cholecystitis or gastroenteritis.

Key constituents of the physical examination include an abdominal exam (with right upper quadrant palpation), vaginal speculum exam (that includes inspection of the cervix), bimanual exam (to assess cervical motion, adnexal tenderness and pelvic masses), as well as microscopic evaluation of a cervicovaginal discharge sample.