Lymphogranuloma Venereum (LGV): Symptoms, Testing & Treatment in the UK

Lymphogranuloma venereum, commonly known as LGV, is a sexually transmitted infection (STI) caused by specific invasive strains of the bacterium Chlamydia trachomatis (specifically serovars L1, L2, and L3). While it belongs to the same family as common chlamydia, LGV is significantly more aggressive and targets the lymphatic system.

Historically more common in tropical climates, the UK has seen a steady rise in LGV cases over the last two decades, particularly among men who have sex with men (MSM). According to UK Health Security Agency (UKHSA) data, LGV is a significant public health concern because, if left untreated, it can lead to chronic, irreversible damage to the genital and rectal tissues.

LGV typically progresses through three distinct clinical stages. Recognising these early is vital for effective treatment.

Stage 1: The Primary Lesion

Between 3 and 30 days after exposure, a small, painless blister or ulcer may appear at the site of infection (the penis, vagina, or rectum). Because it is painless and often disappears within a few days, many patients do not notice it.

Stage 2: Inguinal Syndrome

Occurring 2 to 6 weeks after the initial sore, the bacteria spread to the lymph nodes. This causes the 'buboes'—painful, firm swellings in the groin. In the UK, this is often accompanied by systemic symptoms such as fever, chills, and muscle aches.

Stage 3: Anogenital Syndrome

If the infection is rectal, patients may skip the groin swelling and experience proctitis. Symptoms include rectal pain, discharge (which may contain blood or pus), tenesmus (a constant feeling of needing to empty the bowels), and constipation. This stage requires urgent medical attention to prevent permanent scarring.

LGV is transmitted through unprotected vaginal, anal, or oral sex, as well as through the sharing of sex toys. It is not passed through casual contact like hugging or sharing towels.

Diagnosis in the UK follows BASHH (British Association for Sexual Health and HIV) guidelines. If you suspect you have been exposed, a clinician will take a swab from the affected area (urethra, rectum, or throat). Standard chlamydia tests may return a 'positive' result, but specialized NAAT (Nucleic Acid Amplification Test) laboratory testing is required to confirm if the strain is specifically LGV.

• Rectal Swabs: Highly recommended for those with rectal symptoms.
• Urethral Swabs: For symptoms involving the penis.
• Blood Tests: While less common for diagnosis, they may be used in specialist settings to check for antibodies.

The good news is that LGV is curable with the correct course of antibiotics. Unlike standard chlamydia, which often requires a short course of medication, LGV requires a more intensive approach to clear the bacteria from the lymphatic system.

The first-line treatment recommended by NICE (National Institute for Health and Care Excellence) is:

• Doxycycline: 100mg taken twice daily for 21 days.
• Erythromycin: May be used as an alternative if the patient is pregnant or cannot tolerate doxycycline.

It is crucial to complete the full 21-day course, even if symptoms vanish after the first week. Patients should abstain from all sexual contact until they—and their recent partners—have completed treatment to prevent reinfection.

Sexual health concerns can be sensitive, and many people feel more comfortable initiating the conversation in a private, digital environment. You should consider booking a consultation to speak to a GP online if:

• You have noticed unusual lumps or swellings in your groin area.
• You are experiencing persistent rectal pain or discharge.
• You have been notified by a partner that they have tested positive for an STI.
• You require a referral or guidance on where to access specialist LGV testing in your local area.

An online doctor can review your symptoms, provide evidence-based advice, and help you understand the next steps for testing and treatment. If your symptoms are severe, they may advise you to visit a physical sexual health clinic for immediate swabs and clinical examination.

Preventing LGV involves the same principles as other STIs: using condoms for penetrative sex and dental dams for oral sex. Regular STI screening is also essential, especially for individuals with multiple partners or those who belong to high-incidence groups in the UK.

If treated early, the outlook is excellent. However, chronic untreated LGV can lead to lymphoedema (severe swelling caused by lymph node blockage) or fistulas (abnormal tunnels between the rectum and other organs). Early intervention is the best way to ensure long-term health and wellbeing.