17 Most studies of the microbiology of the lower genital tract relate to the vaginal flora. The microenvironment at this site is a self‐regulating, self‐cleaning, resilient yet delicate ecosystem. There is not so much information about the vulva. The vulva of the newborn child is sterile but after the first 24 hours of life it gradually acquires, from the skin, vagina and intestine, a rich varied flora of nonpathogenic organisms. The vulval flora is mainly composed of Gram‐positive bacteria such as Staphylococcus species including S. aureus, S. epidermidis, S. saprophyticus and S. pyogenes. The close proximity to the vagina, the urethra, and the anus, may result in contamination with the flora typical for those sites, such as lactobacilli, candida species, Group B Streptococcus, and Gardnerella vaginalis. In certain situations, (a moist environment, antibiotic medication, radiotherapy and chemotherapy, immunosuppression) these microorganisms may increase their pathogenicity, causing a vulvitis. Infections affecting the vulva and vagina may be sexually or nonsexually transmitted. The main sexually transmitted infections (STIs) are listed in Table 17.1 by their causative organisms. More than one sexually transmitted infection may occur in the same patient and therefore any patient with a suspected or confirmed STI must be referred to a genito‐urinary clinic for full screening, contact tracing and expert management. Table 17.1 Major sexually transmitted infections. Trichomoniasis is a common sexually transmitted infection with over 3 million people infected in the United States each year. It can be associated with prematurity and low birth weight if it occurs during pregnancy. There is also a link with HIV infection and trichomoniasis may increase the risk of transmission of HIV. The causative organism is the protozoan Trichomonas vaginalis. It is found in the vagina but 90% of infected women have urethral infection. The main symptom is a vaginal discharge which may be malodorous. Dysuria and vulval pruritus are also common. However, up to 50% of patients do not report any symptoms. The discharge is typically foamy but can vary in type and a ’strawberry’ like appearance is seen on the cervix. Vestibular erythema and posterior vulvitis is seen secondary to the vaginal discharge. The diagnosis can be made by direct microscopy of a wet preparation as the motile organisms are easily seen. The infection can then be confirmed on culture. Several nucleic acid amplification tests are now used, and these are regarded as the most sensitive tests. The treatment is a single dose of 2 g of metronidazole. The patient should be referred to a genito‐urinary clinic for contact tracing and screening for other STIs. British Association for Sexual Health and HIV: CDC Guidelines on Treatment: Chlamydia trachomatis is a bacterium with two distinct biovars that cause genital disease (D‐K) and eye disease (A‐C) respectively. Genital chlamydia is one of the most common sexually transmitted infections in the young, affecting up to 10% of sexually active women under the age of 24. Rectal and pharyngeal infections may also occur but are less common. The infection is asymptomatic in 70% of infected females. A vaginal discharge or bleeding may occur with or without abdominal pain or dysuria. If untreated, 40% of patients may then go on to develop pelvic inflammatory disease. Clinical examination is often normal. A purulent discharge and contact bleeding in the vagina may be seen. Cervical or vulvo‐vaginal swabs or urine samples are taken and nucleic acid amplification techniques are used to test for the organism. The recommended treatment is 1 g of azithromycin. CDC guidelines on treatment: Lymphogranuloma venereum (LGV) is a sexually transmitted infection where the causative organism is a serovar of Chlamydia trachomatis, most commonly L2. The incidence has been increasing, especially among HIV‐positive men who have sex with men. In women, the initial lesion is a painless, shallow erosion on the vulva or vaginal wall. Painful regional lymphadenopathy is common and buboes may develop. If the disease spreads, destructive lesions, fistulae, chronic granulomatous inflammation and oedema may ensue (Figure 17.1). Figure 17.1 Lymphogranuloma venereum: sinuses. Nucleic acid amplification tests are now routinely used. Doxycycline 100 mg bd for 21 days is used as a first‐line treatment. Other antibiotics include minocycline or erythromycin. CDC 2015 guidance: The causative organism of gonorrhoea is Neisseria gonorrhoea, a Gram‐negative diplococcus. Transmission is via direct contact with infected secretions and common sites of infection are the cervix, urethra, rectum and pharynx. About half of the females infected are asymptomatic. A vaginal discharge, dysuria and abdominal pain may occur. Examination may be normal but a purulent discharge is sometimes visible. Infection may spread to cause Bartholin’s gland enlargement and even abscess formation. Further spread can lead to pelvic inflammatory disease and even disseminated infection with arthritis and cutaneous lesions. Nucleic acid amplification tests are increasingly used as the most sensitive test. The organisms can be seen on direct microscopy of a discharge and then cultured. A cephalosporin is the treatment of choice but other regimens are published and expert advice should be sought as there are problems with antibiotic resistance. British Association for Sexual Health and HIV: CDC guidelines and patient information: Syphilis is due to infection with the spirochaete Treponema pallidum. It presents in one of four different stages: primary, secondary, latent, and tertiary. Primary syphilis is typically acquired by direct sexual contact with an infectious lesion. There has been rise in the number of cases of syphilis in Europe and the United States since the 1990s. The causative organism enters via small breaks in the mucosa or skin. After 3 to 90 days from the initial exposure (average 21 days) a skin lesion appears at the point of contact. This chancre contains millions of spirochaetes. These spread via the bloodstream to other organs at this stage and transplacental transmission is also common at this point. This may give rise to systemic symptoms associated with secondary syphilis. Lesions occur on the vulva in only 2–7% of cases as the most common location in women is the cervix (44%). In 80% of cases, inguinal lymph node enlargement is present. The lesion may persist for 3 to 6 weeks without treatment. This is described in many patients as a single, firm, painless, non‐itchy ulcer (Figure 17.2) but they may be painful in 30%. They usually have a clean base and sharp borders measuring between 0.3 and 3.0 cm in size. The lesion, however, may take on almost any form. In the classic form, it evolves from a macule to a papule and finally to an erosion or ulcer. Occasionally, multiple lesions may be present. Figure 17.2 Primary chancre of syphilis on right inner labium majus. Secondary syphilis occurs approximately 4 to 10 weeks after the primary infection. While secondary disease is known for the many different manifestations (it has been termed the ‘great mimicker’), symptoms most commonly involve the skin. It presents as a symmetrical, reddish‐pink, non‐itchy rash on the trunk and extremities, including the palms and soles. Oral ulceration (‘snail track’ ulcers) and condylomata lata occur at this stage. The condylomata lata are warty lesions on the vulva and perianal area. The acute symptoms usually resolve after 3 to 6 weeks; however, about 25% of people may present with a recurrence of secondary symptoms. Many people who present with secondary syphilis (40–85% of women, 20–65% of men) do not report previously primary syphilis. Latent syphilis is defined as having serologic proof of infection without symptoms of disease. It usually presents less than 1 year after secondary syphilis or later. Late latent syphilis is asymptomatic and not as contagious as early latent syphilis. Tertiary syphilis may occur approximately 3 to 15 years after the initial infection and may be divided into three different forms: gummatous syphilis (15%); late neurosyphilis (6.5%); and cardiovascular syphilis (10%). Without treatment, a third of infected people develop tertiary disease. People with tertiary syphilis are not infectious. Treatment of early syphilis is a single dose of intramuscular benzathine penicillin G. Doxycycline and tetracycline are alternative choices for those allergic to penicillin. It is recommended that treated patients avoid sexual intercourse until the sores are healed. Expert advice must be taken for pregnant patients for the management of potential congenital syphilis.
Vulval Infection – Sexually Transmitted
Normal flora
Protozoa
Trichomoniasis
Bacteria
Chlamydia
Lymphogranuloma venereum
Gonorrhoea
Syphilis
Chancroid
Donovanosis
Viruses
Herpes simplex infection
Human papilloma virus infection
Molluscum contagiosum
Parasites
Scabies
Pubic lice
Trichomoniasis
Pathophysiology
Clinical features
Diagnosis
Basic management
Further reading
Useful Web Site for Patient Information
Chlamydia
Clinical Features
Diagnosis
Treatment
Further reading
Useful Web Site for Patient Information
Lymphogranuloma Venereum
Clinical features
Diagnosis
Treatment
Further reading
Useful Web Site for Patient Information
Gonorrhoea
Clinical features
Diagnosis
Treatment
Further reading
Useful Web Sites for Patient Information
Syphilis
Pathophysiology
Clinical features
Treatment
Further reading
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