Sexually transmitted infection caused by Chlamydia trachomatis

Aetiology

• The disease was largely confined to tropical regions of the world but there are now outbreaks arising locally in Europe, America and the UK
• Risk factors include unprotected sexual intercourse, multiple sexual partners, receptive anal intercourse, male gender and prostitution

Clinical features

• The clinical presentation is divided into primary, secondary and tertiary patterns

Primary

• Usually presents with a painless papule or shallow ulcer/erosion that occurs 3 days to 3 weeks after exposure
• May be groups of lesions resembling herpes infection

Secondary

• Usually occurs 10-30 days after exposure
• Buboes (grossly enlarged tender nodes) form in the regional lymph drainage
• May be symptoms of systemic illness such as fever, headache, nausea, vomiting, lethargy and arthralgia

Tertiary

• Late presentation can occur up to 20 years after infection
• Patients may complain of anal itching, bloody mucopurulent anal discharge, rectal pain and tenesmus, passage of very thin stools with constipation or weight loss
• Esthiomene - an 'eating away' of the genitalia - may affect women

Investigations

• Full STI screening: NAATs
• CT imaging: may be used to assess the extent of lymphadenopathy and to look for alternative causes