⭐ PID – THE 20% THAT GIVES 80% MARKS

1. Definition:

Ascending infection of the upper genital tract (endometrium → fallopian tubes → ovaries → pelvis).

2. Most common causes:
• Chlamydia trachomatis (most common)
• Neisseria gonorrhoeae
• Polymicrobial (anaerobes, Gardnerella, Mycoplasma genitalium).
3. Classic triad:
• Lower abdominal pain
• Cervical motion tenderness (CMT)
• Adnexal tenderness
4. Other signs:
• Fever
• Abnormal vaginal discharge
• Post-coital bleeding
• Dyspareunia
5. Complications (VERY HIGH-YIELD):
• Infertility (tubal scarring)
• Ectopic pregnancy
• Chronic pelvic pain
• Fitz-Hugh–Curtis syndrome = RUQ pain + violin-string adhesions
• Tubo-ovarian abscess (TOA)
6. Diagnosis:

– Clinical diagnosis

– Pregnancy test to exclude ectopic

– STI testing (NAAT)

– Ultrasound (for TOA only)

7. Treatment:

Outpatient:

1. Ceftriaxone (gonorrhea cover)
2. Doxycycline (chlamydia)
3. + Metronidazole (anaerobes)

Inpatient:

4. IV ceftriaxone + doxycycline + metronidazole

OR

5. Clindamycin + gentamicin
8. Hospitalize if:
• TOA
• Severe illness
• Pregnancy
• No response to oral therapy
• Cannot tolerate PO
9. Sexual partner management:
• Treat partners for STIs
• Abstain from sex until therapy completed
10. Prevention:

– Safe sex

– Screening for chlamydia in <25 yrs & high-risk women

🔬 COMPLETE, EASY-TO-UNDERSTAND MICROBIOLOGY & PATHOPHYSIOLOGY

1. How PID Happens (Ascending Infection)

– Infection begins in cervix → spreads upward.

– Cervical barrier lost due to menstruation, intercourse, instrumentation.

– Organisms ascend to:

• Endometrium (endometritis)
• Fallopian tubes (salpingitis)
• Ovaries (oophoritis)
• Pelvic peritoneum (pelvic peritonitis)

Chlamydia → chronic, silent damage

Gonorrhea → acute, purulent inflammation

2. Organisms Involved

A. Primary STIs

• Chlamydia trachomatis → MOST COMMON cause
• Neisseria gonorrhoeae

B. Anaerobes (important in severe PID or TOA)

• Bacteroides
• Prevotella
• Peptostreptococcus

C. BV-associated organisms

• Gardnerella vaginalis

D. Atypicals

• Mycoplasma genitalium (emerging major cause)

PID is therefore polymicrobial.

3. Risk Factors

• Age <25
• Multiple sexual partners
• Previous PID
• Chlamydia/gonorrhea infection
• Recent IUD insertion (first 3 weeks only)
• Douching
• New sexual partner
• Poor condom use

4. Clinical Presentation

A. Symptoms

• Lower abdominal pain
• Abnormal vaginal discharge
• Intermenstrual or post-coital bleeding
• Dyspareunia
• Dysuria
• Fever, chills
• Nausea/vomiting (severe cases)

B. Signs

• Cervical motion tenderness (CMT)
• Adnexal tenderness
• Uterine tenderness
• Mucopurulent cervical discharge
• Fever > 38.3°C
• Elevated ESR / CRP

5. Associated Conditions

A. Endometritis

Uterine tenderness + abnormal bleeding.

B. Salpingitis

Most common site → tubal scarring → infertility.

C. Oophoritis

Rare alone, usually part of TOA.

D. Tubo-ovarian Abscess (TOA)

– Fever, severe pain, adnexal mass

– Requires hospitalization

– Risk of rupture → surgical emergency

E. Fitz-Hugh–Curtis Syndrome

Perihepatitis

→ RUQ pain + shoulder tip pain

→ Laparoscopy shows violin-string adhesions

6. Diagnosis (Clinical Diagnosis)

PID is often clinical, because waiting for lab tests delays treatment.

Minimal criteria (any 1 of 3)

• CMT
• Uterine tenderness
• Adnexal tenderness

Supportive findings

• Fever
• Mucopurulent discharge
• ↑ ESR / CRP
• NAAT positive for chlamydia/gonorrhea
• WBCs on microscopy

Imaging

• Ultrasound only to detect:
• TOA
• Hydrosalpinx
• Free fluid

Otherwise, ultrasound is often normal.

Do NOT miss pregnancy test

→ To rule out ectopic pregnancy.

7. Treatment Details

Outpatient (Recommended for most)

Ceftriaxone IM single dose

+ Doxycycline 100 mg BD 14 days

+ Metronidazole 500 mg BD 14 days

Inpatient indications:

• TOA
• Pregnancy
• Severe illness or high fever
• Vomiting or unable to tolerate oral therapy
• No improvement after 48–72 hrs
• Suspected surgical emergency (appendicitis, ectopic)

Inpatient Regimens

1. Ceftriaxone IV + Doxycycline + Metronidazole
2. Clindamycin + Gentamicin (good for TOA)
3. Ampicillin/Sulbactam + Doxycycline

TOA management

• Drainage (image-guided) if large
• IV antibiotics
• Surgery if ruptured

8. Long-Term Complications (Exam Gold)

• Infertility (tubal scarring)
• Ectopic pregnancy (damaged tubes)
• Chronic pelvic pain
• Recurrent PID
• Adhesions
• TOA
• Perihepatitis (Fitz-Hugh–Curtis)

Even one episode of PID increases infertility risk.

⭐ THE MUST-MEMORISE SUMMARY (20% → 80% SCORING BLOCK)

1. PID = ascending infection of upper genital tract.
2. Causes: Chlamydia (most common), Gonorrhea, anaerobes.
3. Symptoms: pelvic pain + CMT + discharge.
4. Complications: infertility, ectopic pregnancy, TOA, FHCS.
5. Diagnosis = clinical; pregnancy test essential.
6. Treatment: Ceftriaxone + Doxycycline + Metronidazole.
7. Admit if severe, pregnant, TOA, or no improvement.
8. Treat the partner + abstain from sex until completed therapy.
9. Prevention: screening for chlamydia, condoms.
10. TOA → treat aggressively (IV antibiotics ± drainage).