What is Pelvic Inflammatory Disease (PID)

Pelvic inflammatory disease (PID) is an inflammation of the female reproductive organs inside the pelvis such as the cervix, uterus, fallopian tubes and ovaries.

It is almost always due to infection by sexually transmitted infections (STIs) or overgrowth of vaginal normal flora. It can be fatal if left untreated. There are many microorganisms that are involved in the development of PID.

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When the cervix is infected and inflamed, it is called cervicitis. Infection of the fallopian tubes is called salpingitis. Endometritis is when the infection involves the endometrium. Inflammation of the ovaries is called oophoritis.

With PID multiple female reproductive organs are inflamed at once. There may be combination of cervicitis and salpingitis at the same time.

Sometimes the infection and inflammation is not limited in the reproductive organs but involves surrounding tissues such as peritoneum and cause peritonitis.

Causes

PID is caused by bacterial infection most commonly sexually transmitted infections. Studies show that 50% of patients with acute PID test positive for Gonorrhoeae. Common bacteria involved are:

• Neisseria Gonorrhoeae (common)
• Chlamydia Trachomatis (common)
• Mycoplasma Genitalium
• Hemophilus influenzae
• Streptococcus Agalactiae
• Mycoplasma Hominis
• Ureaplasma species
• Gardnerella Vaginalis
• Anaerobes
• Peptococcus species
• Eschericia Coli

Sometimes acute pelvic inflammatory disease (PID) is caused by viruses such as:

• Herpes Simplex Virus 2 (HSV-2) and
• Cytomegalovirus (CMV)

Risk Factors of Developing PID

The risk factors that increase the chances of getting PID are:

• Presence of STI or bacterial vaginosis (infection of the vagina by non-sexually transmitted bacteria)
• Previous episode of PID
• Multiple sexual partners who do not use condom
• Low socioeconomic status
• Vaginal douching
• Young age: PID is not seen in women after menopause and before menarche
• Non white race
• Gynecological procedures such as endometrial biopsy or curettage following incomplete miscarriage or termination of pregnancy

PID is very rare during pregnancy.

Clinical Features of PID

Pelvic inflammatory disease have the following symptoms:

Symptoms

• Lower abdominal pains
• Foul smelling vaginal discharge
• Lower back pain
• Fever
• Fatigue
• Nausea and vomiting sometimes if the infection has spread to the peritoneum (local peritonitis)
• Irregular menstruation
• Bleeding after sexual intercourse
• Dyspareunia: described as pain during sexual intercourse.

Pain during sexual intercourse can also occur in people with endometriosis, so if there are no other associated symptoms its unlikely to be pelvic inflammatory disease.

Signs of PID

Objective clinical findings during physical examination on someone with pelvic inflammatory disease are:

• Uterine tenderness: it is defined as tenderness on deep palpation on the hypogastric region or suprapubic area.
• Adnexal tenderness: tenderness on left or right side pelvis where adnexa structures are located (fallopian tubes, ovaries and ligaments).
• Cervical motion tenderness: described as pain when the cervix is moved during PV glove examination.
• Pyrexia with temperature above 38°C (101°F).
• Tachycardia (pulse rate > 100 beats per min)
• Hypotension (systolic BP below 90) with high pulse rate is a sign of septic shock that needs emergency treatment.

Foul smelling discharge may sometimes be seen on speculum examination.

Depending on the grade of PID (to be mentioned shortly), there may also be localized peritonitis identified by rebound tenderness on the pelvic are or generalized peritonitis where the whole peritoneum is inflamed.

Late signs

1. Local peritonitis: rebound tenderness on the pelvis
2. Generalized peritonitis: Rebound tenderness on the whole abdomen
3. septic shock: Low BP, High Pulse rate, altered mental state, and high grade fever.
4. A palpable mass on the adnexal area suggest presence of tubo-ovarian abscess, a complication of PID.

Investigations in PID

Diagnosis of PID is based mainly on high index of suspicion, this means physicians should be alert and suspect PID in people with above mentioned signs and symptoms.

The US Center for Disease Control and Prevention (CDC) recommends empiric treatment of PID in any sexually active young lady that has pelvic pain with no identifiable cause AND:

1. Cervical motion tenderness OR
2. Adnexal tenderness OR
3. Uterine tenderness

Full Blood Count (FBC) may show elevated white cell count.

Erythrocyte Sedimentation Rate (ESR) above 40 and C-reactive protein (CRP) above 60 support the diagnosis although not specific for PID. They are inflammatory markers that become elevated in the blood whenever there is inflammation going on.

If vaginal discharge is present, a vaginal swab for microscopy, culture and sensitivity (M, C & S) is done to identify the causative organism and what treatment is responds on.

An ultrasound can be done, which may show thickened fluid filled tubes and can reveal presence of tubo-ovarian abscess.

PID should be treated based on clinical suspicion, additional investigation can be done while treatment is already started. There is no benefit in waiting for blood test results before commencing treatment.

Laparoscopy is the most sensitive and specific test for diagnosing PID. Its main disadvantages are that it is invasive, requires general anaesthesia and generally expensive.

Stages of PID

There are four clinical stages of PID which grade the severity of the infection. The table below describes PID stages I-IV.

Treatment of PID

Treatment of pelvic inflammatory disease (PID) is done to achieve the following:

• Eradication of infection
• Relief of symptoms
• Minimize long term complications of PID

Infection is treated with antibiotics empirically.

For Stage (I) PID:

• Azithromycin 1g oral single dose plus
• Ceftriaxone 250mg Intramuscular (IM) single dose and
• Metronidazole 2g oral single dose usually treat the infection successfully .
• Analgesia and NSAIDs such as Ibuprofen or Naproxen and Paracetamol (Acetaminophen) is added to reduce pain and inflammation inside pelvis structures.

Stages II-IV need hospitalization and longer duration of treatment with intravenous antibiotics. It is recommended to involve gynecologist for treatment of stages III and IV PID.

Patients not improving within 72 hours should be re-evaluated for possible surgical intervention.

Complications of PID

Complications and long term sequelae of PID are

• Ectopic Pregnancy
• Recurrent PID
• Infertility
• Chronic Pelvic pain

It is important for young women to treat abnormal vaginal discharge and Sexually Transmitted Infections (STIs) before they complicate to PID. Condom use protects against most STIs although it does not offer protection against HPV.

Prevention

There are many health education tips and ways to prevent pelvic inflammatory disease.

Practicing safe sex is very important in preventing sexually transmitted infection. This includes consistent correct condom use for those who have multiple sexual partners. Reducing number of sexual partners is even better for your health

Male sexual partners should be treated even if they do not have symptoms of STIs as they may be carriers. So whenever a female is treated, she should be encouraged to bring a partner or sexual partners for treatment as well.

Frequent vaginal douching is discourage as it causes imbalance in vaginal flora.

Wiping from front to back is important as it prevents microbes from the anus from infecting both the vagina and urinary tract.

Differential Diagnosis

Pelvic Inflammatory Disease may present with signs and symptoms that are sometimes similar to the following conditions:

• Ectopic Pregnancy
• Acute Appendicitis
• Ovarian Cyst Rupture
• Endometriosis

Treatment refences:

1. Standard Treatment Guidelines and Essential Medicines List for South Africa Adult Hospital_Chapter 5: Gynaecology; Version 1.0, 2020-04_June 2024.
2. MSD Pro: https://www.msdmanuals.com/professional/gynecology-and-obstetrics/vaginitis-cervicitis-and-pelvic-inflammatory-disease/pelvic-inflammatory-disease-pid#Treatment_v1063552