Anogenital warts are amongst the commonest sexually acquired infections with ever growing numbers of people seeking treatment. The causative agent is human papillomavirus (HPV) especially types 6 and 11. HPV is acquired by direct sexual contact with a person with either clinical or subclinical infection. Neonates may acquire HPV from an infected birth canal which may result either in anogenital warts or in laryngeal papillomas. The incubation period may range from 2 weeks to 8 months or even longer.
Warts may develop around the external genitalia in women, usually starting at the fourchette and may involve the perianal region. The vagina may be infected. Flat warts may develop on the cervix that may not be easily visible on routine examination. Such lesions may have an association with cervical intraepithelial neoplasia and may be diagnosed on cervical cytology or at colposcopy. In men the penile shaft and sub preputial space are the commonest sites although warts may involve the urethra and meatus. Perianal lesions are more common in men who practise anoreceptive intercourse but may be found in any patient. The rectum may become involved. Warts may become more florid during pregnancy or in immunosuppressed patients.
The diagnosis is essentially clinical. It is important to differentiate condylomata lata of secondary syphilis.Unusual lesions should be biopsied if the diagnosis is in doubt. Up to 30% of patients may have coexisting infections with other STDs and a full screen is important.
Local agents include podophyllin extract 10-25%, podophyllotoxin and trichloroacetic acid. In extensive or recalcitrant infection cryotherapy, electrocautery or laser ablation is indicated. Podophyllin is contraindicated in pregnancy. Sexual contacts should be examined and treated if necessary. In view of the difficulties of diagnosing subclinical HPV, condoms should be used for up to 8 months after treatment. Because of the association of HPV with cervical intraepithelial neoplasia women with warts and female partners of men with warts are advisedto have cervical cytology carried out annually. Some clinics advocate colposcopy for all women with HPV infection.
Sexual contacts should be screened and offered vaccine if they are not immune.
Trichomonas vaginalis (TV) is a flagellated protozoon which is predominantly sexually transmitted. It is able to attach to squamous epithelium and can infect the vagina and urethra. Infected women may, unusually, be asymptomatic. Commonly the major complaints are of vaginal discharge which may be offensive and of local irritation. Examination often reveals a frothy yellowish vaginal discharge and erythematous vaginal walls. The cervix may have multiple small haemorrhagic areas which lead to the description ‘strawberry cervix’. In men the infection is usually asymptomatic but may be a cause of NGU.
Phase-contrast microscopy of a drop of vaginal discharge shows TV swimming with a characteristic motion. Many polymorphonuclearleucocytes are also seen. Culture techniques are good and confirm the diagnosis.
Metronidazole 400 mg twice daily for 7 days is the treatment of choice. There is some evidence of resistance although a single dose of 2 g can be given. Nimorazole may be effective in these cases. Topical therapy with clotrimazole may be effective but if extra-vaginal infection exists this may not be eradicated and vaginal infection reoccurs. It is important that male partners are followed up especially as they are likely to be asymptomatic.
‘ulvovaginal infection with Candida albicans is extremely common. The organism is also responsible for balanitis in men. Candida may be isolated from the vagina in a high proportion of women of childbearing age, many of whom will have no symptoms. The role of Candida as pathogen or commensal is difficult to disentangle and it may be changes in host environment which allow the organism to produce pathological effects. Predisposing factors include pregnancy, the oral contraceptive pill, diabetes and broadspectrum antibiotics. Immunosuppression can produce more florid infection.
In women pruritus vulvae is the dominant symptom. Vaginal discharge is present in varying degree. Many women have only one or occasional isolated episodes but in a minority of patients the symptoms may be recurrent or chronic. Examination reveals erythema and swelling of the vulva with broken skin in severe cases. The vagina may contain adherent curdy discharge. Men may have a florid balanoposthitis. More commonly self-limiting burning penile irritation immediately after sexual intercourse with an infected partner is described. Diabetes must be excluded in men with balanoposthitis.
Microscopic examination of a smear from the vaginal wall reveals the presence of spores and mycelia. Culture of swabs should be undertaken but may be positive in women with no symptoms. It is important to exclude Trichomonas and bacterial vaginosis in women with itch and discharge.
Pessaries or creams containing one of the imidazole antifungals such as clotrimazole used intravaginally are usually effective. Nystatin is also useful. The triazole drugs such as fluconazole 150 mg single dose or itraconazole 200 mg twice in 1 day may be used systemically in circumstances where topical therapy has failed or is inappropriate. Although the evidence for sexual transmission of Candida is slight, male partners of women with frequent recurrent episodes should be reviewed and possibly treated.
Bacterial vaginosis (BV) or non-specific vaginosis is a disorder characterized by an offensive vaginal discharge. The aetiologyand pathogenesis is unclear but the normal lactobacilli of the vagina are replaced by a mixed flora of Gardnerella vaginalis, anaerobes including Bacteroides, and Mycoplasma hominis. Amines and their breakdown products from the abnormal vaginal flora are thought to be responsible for the characteristic odour associated with the condition. As vaginal inflammation is not part of the syndrome the term vaginosis is used rather than vaginitis. It is not clear to what extent BY is a sexually transmitted condition