Pelvic inflammatory disease

Genital tuberculosis

• Almost always secondary, reaching the genital tract by the blood from a lung focus (often healed), less often from the peritoneum.
• Sites: fallopian tubes in 90–100% (bilateral), endometrium in about half or more, ovaries less often, cervix and vulva rarely.
• Tubes: thickened and studded with yellow caseous tubercles, beaded and rigid on HSG, yet fimbriae often open and everted (tobacco-pouch end), unlike pyogenic PID, which seals the fimbriae. Open fimbriae do not mean a working tube; the lumen is often blocked further in.
• Endometrium is shed monthly, so take an endometrial biopsy in the premenstrual week for histology (caseating granulomas with Langhans giant cells), culture and GeneXpert (PCR that also detects rpoB mutations, signalling rifampicin resistance).
• Destruction of the basal endometrium causes intrauterine adhesions: scanty periods then amenorrhoea with normal FSH.
• Presents with primary infertility, menstrual upset, pelvic pain or ascites.

Tuberculosis elsewhere: the same immunology

• Protection depends on Th1 cells: IFN-gamma activates macrophages, which wall off bacilli in granulomas. In leprosy the same principle explains the spectrum: strong Th1 immunity gives tuberculoid disease with few lesions and few bacilli; weak Th1 (Th2-dominant) gives lepromatous disease with widespread lesions full of bacilli.
• Peritoneal tuberculosis mimics ovarian cancer: ascites with fine septations, thickened omentum, evening fevers, weight loss and a high CA-125 (any peritoneal inflammation raises it). The ascitic fluid is a lymphocyte-rich exudate with high adenosine deaminase; laparoscopy shows miliary tubercles.
• Tuberculous meningitis: subacute headache and neck stiffness over weeks; CSF has lymphocytes, very high protein and low glucose.
• A tuberculous ulcer of skin or bowel has undermined edges; intestinal TB favours the ileocaecal region.
• Ethambutol causes optic neuritis with red–green colour loss; isoniazid causes neuropathy (give pyridoxine).

Pelvic inflammatory disease

• Ascending infection from the cervix to endometrium, tubes, ovaries and peritoneum. Chlamydia trachomatis is the commonest cause (often silent); gonorrhoea causes acute purulent salpingitis; anaerobes and *Mycoplasma genitalium* follow.
• Onset is often just after menstruation: the cervical mucus plug is lost, menstrual blood is a culture medium and retrograde flow carries organisms upward. IUCD insertion and instrumentation also introduce infection.
• Complications: tubal infertility, ectopic pregnancy, chronic pelvic pain, tubo-ovarian abscess, and Fitz-Hugh–Curtis perihepatitis (violin-string adhesions between liver and diaphragm).
• Chlamydial tubal damage is partly immune: chlamydial heat shock protein 60 drives delayed hypersensitivity and fibrosis.
• Actinomyces israelii is linked with a long-standing IUCD: pelvic abscess with sulphur granules.
• Treatment: ceftriaxone (gonococcus), doxycycline (chlamydia, mycoplasma), metronidazole (anaerobes).

Chlamydia and gonorrhoea

• Why NAAT: it amplifies organism DNA or RNA, so it is the most sensitive test and works on self-taken swabs. Because nucleic acid from dead organisms persists, a test of cure (advised in pregnancy) is done no sooner than 3 weeks after treatment. A positive test of cure more often means reinfection from an untreated partner than resistance.
• Gonococcal culture: Thayer–Martin (modified chocolate agar) contains vancomycin, colistin and nystatin to suppress the normal genital flora (Gram-positives, Gram-negatives and fungi), and is incubated in 5–10% carbon dioxide. Swabs need prompt plating or transport medium.
• No lasting immunity to gonorrhoea: antigenic variation of the pili (and Opa proteins) lets the organism escape antibodies, so reinfection is common.
• Chlamydia serovars D–K are genital; L1–L3 cause lymphogranuloma venereum (painful inguinal buboes, groove sign).

Vaginal discharge

• Normal defence: oestrogen-driven glycogen feeds lactobacilli, which make lactic acid (pH about 4) and hydrogen peroxide.

• Whiff test: adding 10% KOH releases volatile amines (trimethylamine, putrescine, cadaverine) made by anaerobes; positive in BV and also in trichomoniasis.
• *Trichomonas* is a flagellated protozoan with no cyst stage: it dies quickly outside the body and spreads almost only by sex. On a wet mount it is seen by its jerky motility, which stops as the sample cools, so a delayed slide is falsely negative (still trichomonads look like pus cells); NAAT is more sensitive.
• Clindamycin vaginal cream contains mineral oil that weakens latex condoms and diaphragms; metronidazole carries the alcohol warning.
• Candida in pregnancy: a clotrimazole vaginal pessary (longer course, about 7 days); oral fluconazole is avoided. Recurrent candidiasis in a poorly controlled diabetic that fails fluconazole, with small budding yeasts and no pseudohyphae, suggests *Candida glabrata*; culture and speciate. Oesophageal candidiasis (white plaques, odynophagia) signals immunosuppression such as HIV or steroids.

Genital ulcers, warts and lice

• Recurrent respiratory papillomatosis: HPV 6 and 11 acquired at birth from maternal warts cause warty growths on the vocal cords with hoarseness and stridor in early childhood. It is rare, so caesarean section is not offered routinely.
• Pubic lice on a child's eyelashes raise concern about sexual abuse.
• A reactive VDRL with negative TPHA in a woman with recurrent miscarriage suggests antiphospholipid antibodies.

Remember Beaded tubes with open fimbriae mean tuberculosis; closed, swollen tubes mean pyogenic PID.

Exam trap Candida is the only common vaginal infection with a normal acid pH; bacterial vaginosis and trichomonas raise it.

Exam trap Genital tuberculosis reaches the tubes by the blood from a lung focus; it is not an ascending infection like PID.

How FCPS asks about this

• Thickened tubes with tubercles but everted open fimbriae: tuberculous salpingitis.
• Ascites, high CA-125, lymphocytic exudate, high ADA: peritoneal tuberculosis.
• Frothy green discharge, strawberry cervix: trichomoniasis; metronidazole for both partners.
• Screening test for chlamydia: NAAT on a self-taken vulvovaginal swab.
• Why gonorrhoea recurs: antigenic variation of pili.
• Candida in pregnancy: clotrimazole vaginal pessary.
• Commonest cause of PID: Chlamydia trachomatis.