Making a diagnosis of PID on history and examination alone

• These recommendation are based on expert opinion in guidelines on the management of acute pelvic inflammatory disease (PID) from the Royal College of Obstetricians and Gynaecologists [RCOG, 2009], the British Association for Sexual Health and HIV [BASHH, 2005a], and guidelines from the Department of Health and Human Services Centres for Disease Control and Prevention [CDC, 2006].
• Making an accurate clinical diagnosis of PID from the symptoms and signs has been described as 'little better than tossing a coin' [Ross, 2002] and clinicians should have a low threshold for initiating treatment.
• Symptoms and signs for suspected PID lack sensitivity and specificity [RCOG, 2009]. The positive predictive value of making a clinical diagnosis of PID compared with a laparoscopic diagnosis (using laparoscopic diagnosis as the gold standard) is 65–90% [RCOG, 2009]. However, although used as the gold standard, laparoscopy may have a low sensitivity, as 15–30% of women with suspected PID have no signs of acute infection on laparoscopy even when organisms have been found in their fallopian tubes [RCOG, 2009].
• The positive predictive value of a clinical diagnosis of PID also depends on epidemiological factors, including [CDC, 2006]:
• The age of the woman (PID is more common in adolescents).
• Whether the woman is attending a genito-urinary medicine clinic.
• Whether the woman is in a setting where the rates of chlamydia, gonorrhoea, and bacterial vaginosis are high [BASHH, 2005a].
• There is evidence from a large cross-sectional analysis that:
• Adnexal tenderness has a high sensitivity for PID.
• The finding most strongly associated with endometritis was a positive test result for Chlamydia trachomatis or Neisseria gonorrhoeae.

Endocervical and high vaginal swabs

• The recommendation that all women with suspected PID should be tested for C. trachomatis and N. gonorrhoeae (in general by taking endocervical swabs) is based on expert opinion in guidelines from the Royal College of Obstetricians and Gynaecologists [RCOG, 2009], the British Association for Sexual Health and HIV [BASHH, 2005a], the European guideline for the management of pelvic inflammatory disease [Ross et al, 2008], and guidelines from the Department of Health and Human Services Centres for Disease Control and Prevention [CDC, 2006]. These are the most common sexually transmitted organisms detected in PID.
• CKS recommends taking a high vaginal swab to look for other vaginal infections such as bacterial vaginosis and candidiasis.

Erythrocyte sedimentation rate (ESR), C-reactive protein, and leucocyte count

• Increased ESR, C-reactive protein, and leucocyte count supports the diagnosis of PID and can provide useful measures of disease severity [RCOG, 2009].
• However, the ESR or C-reactive protein and white cell count may be normal in mild or moderate PID [Ross et al, 2008].