Likely diagnosis

• Free fluid in the pouch of Douglas (cul-de-sac)
• A few mildly enlarged para-aortic abdominal lymph nodes, up to about 1.1 cm
• Normal uterus, ovaries, kidneys, liver, gallbladder, and no visible pelvic mass or tubo-ovarian abscess.

Important immediate steps

1. See a gynecologist today or within 24 hours.
2. Rule out pregnancy and ectopic pregnancy urgently with a urine/serum beta-hCG test. PID and ectopic pregnancy can look similar, and an ectopic pregnancy can be life-threatening.
3. Usual evaluation:
   • Pelvic/speculum and bimanual examination
   • Pregnancy test
   • Vaginal/cervical swabs or NAAT for gonorrhea and chlamydia, if available
   • Urine test and culture if urinary symptoms
   • CBC, CRP/ESR
   • HIV and syphilis testing if PID is diagnosed
   • Review/possibly repeat ultrasound if symptoms worsen or do not settle

Typical treatment if the doctor confirms mild-to-moderate PID

• Ceftriaxone 500 mg injection into muscle, once
• Doxycycline 100 mg by mouth twice daily for 14 days
• Metronidazole 500 mg by mouth twice daily for 14 days

When hospital admission is needed

• Positive pregnancy test or possible ectopic pregnancy
• Severe pain, high fever, fainting, repeated vomiting, dehydration, or very unwell appearance
• A suspected/confirmed tubo-ovarian abscess
• Unable to take tablets
• No clear improvement within 48-72 hours of starting antibiotics
• Diagnostic uncertainty, for example appendicitis, ovarian torsion, ectopic pregnancy

Sexual-partner and follow-up care

• Avoid sex until the full treatment is finished, symptoms have resolved, and partner(s) have been assessed/treated.
• Sexual partner(s) within the last 60 days should be evaluated and treated for chlamydia/gonorrhea as advised by a clinician.
• Recheck clinically within 48-72 hours. If chlamydia or gonorrhea is found, repeat testing at about 3 months is recommended.
• Finish the entire antibiotic course even if pain/discharge improves. Untreated or recurrent PID can lead to infertility, chronic pelvic pain, ectopic pregnancy, and recurrent infection.

For pain while arranging medical review

• Paracetamol 500-650 mg orally every 6-8 hours as needed
• Maximum 3,000 mg in 24 hours without a clinician's advice. Avoid alcohol and avoid combining with other cold/flu tablets that contain paracetamol.

• Ibuprofen 400 mg after food every 8 hours as needed, for a short period only
• Maximum 1,200 mg/day without prescription.

Go to emergency now if

• Severe or worsening one-sided pelvic/abdominal pain
• Fainting, dizziness, shoulder-tip pain
• Heavy vaginal bleeding
• Fever, persistent vomiting, marked weakness
• Positive pregnancy test
• Pain is not improving within 48-72 hours after clinician-prescribed treatment

Essential today

1. Urine pregnancy test or blood beta-hCG
   • This is the priority. It helps rule out ectopic pregnancy, which can cause pelvic pain and free fluid and requires urgent care.
   • If positive, do not take doxycycline or self-treat with outpatient PID medicines. Go to emergency/gynecology urgently.
2. Gynecologic examination
   • Speculum examination and bimanual pelvic exam for cervical-motion, uterine, or adnexal tenderness.
   • PID is primarily a clinical diagnosis; ultrasound alone cannot confirm it.
3. Vaginal/endocervical swab or first-catch urine NAAT/PCR
   • Chlamydia
   • Gonorrhea
   • Ideally collect before antibiotics, but do not wait for results to start clinician-directed treatment.
4. Urine routine microscopy and culture
   • Particularly if burning urine, frequency, flank pain, or fever, to distinguish UTI/kidney infection.

Usually useful

1. CBC with differential and CRP or ESR
   These assess inflammation/infection severity but cannot prove or exclude PID.
2. HIV test and syphilis serology
   Recommended in confirmed/suspected PID, along with gonorrhea and chlamydia testing, per CDC PID guidance.
3. Hepatitis B surface antigen and hepatitis C antibody
   Consider based on risk factors, vaccination status, and local clinician protocol.

Depending on symptoms/exam

1. Vaginal swab/wet mount or testing for bacterial vaginosis, Candida, and Trichomonas.
2. Repeat transvaginal pelvic ultrasound with Doppler if pain is severe, one-sided, worsening, pregnancy test is positive, or the existing scan was not transvaginal. This helps assess ectopic pregnancy, ovarian torsion/cyst, or tubo-ovarian abscess.
3. Abdominal lymph-node follow-up Because the scan notes para-aortic nodes up to 1.1 cm, your doctor may consider a repeat ultrasound/CT only if nodes persist or symptoms suggest another cause. If there are prolonged fever, weight loss, night sweats, cough, or TB exposure, discuss TB evaluation such as chest X-ray and targeted TB tests. Do not assume the lymph nodes are from PID without clinical review.

Practical order

1. Pregnancy test: urine or blood beta-hCG
   • Most important, to rule out ectopic pregnancy.
   • If positive, urgent gynecology/emergency assessment is needed. Do not self-start doxycycline.
2. Pelvic examination by a gynecologist
   • Checks for cervical-motion, uterine, or adnexal tenderness and abnormal discharge.
3. Chlamydia and gonorrhea NAAT/PCR
   • Vaginal/cervical swab or first-catch urine.
   • Take the sample before antibiotics if possible.
4. CBC with differential and CRP
   • Helps assess infection/inflammation severity.
5. Urine routine examination and urine culture
   • Important if there is burning urine, frequent urination, flank/back pain, or fever.
6. HIV and syphilis blood tests
   • Recommended when PID is diagnosed or suspected.

• Vaginal swab for bacterial vaginosis, Trichomonas, and Candida
• Repeat transvaginal ultrasound with Doppler if severe or one-sided pain, worsening pain, positive pregnancy test, or concern for ovarian cyst/torsion/abscess.

Go to emergency immediately if you have

• Positive pregnancy test plus any pelvic pain or bleeding
• Severe or worsening pain, particularly one-sided
• Dizziness, fainting, weakness, breathlessness, cold sweats, or palpitations
• Shoulder-tip pain
• Heavy vaginal bleeding
• Severe abdominal tenderness, vomiting, or fever

What to do now

1. Do a urine pregnancy test now.
2. If positive, or if pain is severe despite a negative home test, get urgent quantitative blood beta-hCG and transvaginal ultrasound. A single ultrasound or single hCG result may not settle the diagnosis, so repeat hCG/ultrasound after about 48 hours may be needed.
3. Do not self-start doxycycline or assume it is PID until pregnancy is excluded and you have been assessed.

Latest guideline approach for suspected ectopic pregnancy

1. First: assess stability

• Severe or worsening abdominal/pelvic pain
• Fainting, dizziness, pallor, rapid pulse, low blood pressure
• Shoulder-tip pain
• Heavy vaginal bleeding
• Guarding/rigid abdomen or marked tenderness
• Known positive pregnancy test with pain, particularly one-sided pain

2. Confirm pregnancy

• Perform a urine pregnancy test immediately.
• If positive, obtain a quantitative serum beta-hCG.
• A negative very-early urine test does not completely exclude pregnancy if suspicion remains, so serum beta-hCG may be needed.

3. Urgent transvaginal ultrasound

• Whether there is a definite intrauterine pregnancy
• Adnexal mass separate from the ovary, tubal-ring appearance, or extrauterine gestational sac/yolk sac/embryo
• Amount of free pelvic fluid, particularly moderate or large fluid which may represent blood
• Uterus, both ovaries and adnexa, including possible heterotopic pregnancy where relevant

4. If ultrasound does not locate the pregnancy: Pregnancy of Unknown Location (PUL)

• Repeat quantitative beta-hCG about 48 hours later. It should not be drawn earlier than 48 hours for trend interpretation.
• Reassess symptoms at every contact. Symptoms override reassuring hCG trends.
• A rise over 63% in 48 hours makes a developing intrauterine pregnancy more likely, but does not fully exclude ectopic pregnancy. NICE advises repeat TVUS in 7-14 days, or earlier if hCG is at least 1,500 IU/L.
• A smaller rise, plateau, or inadequate fall requires prompt senior gynecology review and repeat imaging/assessment.

5. Baseline tests when ectopic pregnancy is possible

• Quantitative serum beta-hCG
• CBC/hemoglobin and platelet count, especially if bleeding or significant pain
• Blood group and Rh(D) type, with antibody screen and cross-match/group-and-save if bleeding or surgery may be required
• Renal and liver function tests if methotrexate could become a treatment option
• Urinalysis/culture and STI tests if PID remains a competing diagnosis

6. Do not start PID treatment first if pregnancy is possible