Synopsis
Recognise primary and recurrent genital herpes, confirm infection from fresh lesions, relieve pain, use time-sensitive antivirals and manage pregnancy and neonatal exposure safely.
- Primary genital herpes may cause multiple painful vesicles or shallow ulcers, dysuria, tender nodes, fever and profound malaise.
- Recurrent disease is usually shorter and milder, often preceded by tingling or burning in a similar dermatomal area.
- Swab the base of a fresh vesicle or ulcer for HSV-1 and HSV-2 NAAT; blood serology does not confirm the cause of an active ulcer.
Key red flags
Severe pain with inability to pass urine may require admission, analgesia and temporary catheterisation.
Urinary retention, constipation, perineal sensory change or leg symptoms during herpes suggests autonomic and nerve-root involvement.
Investigation priorities
Confirm herpes and distinguish HSV-1 from HSV-2 using material from a fresh vesicle or ulcer base.
Management branches
Painful genital vesicles or ulcers began within five days or new lesions continue to appear.
- Swab a fresh lesion for typed HSV NAAT and obtain syphilis, HIV and site-specific STI testing.
- Start aciclovir 400 mg orally three times daily for five days without waiting for the result.
Key medicines
Aciclovir for first episodeGive 400 mg orally three times daily for five days, starting within five days of onset or while new lesions continue to appear.
Aciclovir episodic recurrenceGive 800 mg orally three times daily for two days, begun during prodrome or immediately when recurrent lesions appear.