Investigation in primary care

• in all women with suspected PID, swabs for Chlamydia trachomatis and Neisseria gonorrhoea should be taken from the endocervix (and urethra) as a minimum (1)
  • a negative swab result does not exclude PID (2).
• endocervical or vaginal pus cells on a wet-mount vaginal smear
  • although the presence of cells is non specific the absence of cells indicates that PID is unlikely (95%) (2)
• other tests such as a pregnancy test (to exclude ectopic pregnancy) (3), urinalysis and urine culture may help exclude other causes of lower abdominal pain
  

Tests generally undertaken in secondary care environment may also include:

• FBC (leucocytosis), ESR (raised), CRP (raised); useful in assessing disease severity (3) but can be normal in mild or moderate disease (1)
• other tests which may be useful include - LFTs (raised in perihepatitis) and blood cultures (if pyrexial)

Advice may be required from microbiology and genito-urinary medicine (GUM) departments concerning current diagnostic methods for causes of PID. (1)

Reference:

1. Workowski KA, Bachmann LH, Chan PA, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep. 2021 Jul 23;70(4):1-187.

2. 2018 United Kingdom National Guideline for the Management of Pelvic Inflammatory Disease. British Association for Sexual Health and HIV (BASHH - 2018, last updated 2019)

3. Curry A et al. Pelvic Inflammatory Disease: Diagnosis, Management, and Prevention. Am Fam Physician. 2019 Sep 15;100(6):357-364.