Herpes simplex virus

Question 1

What are the types of herpes simplex

Answer 1

HSV-1: oro-labial herpes simplex infection → cold sores or gingivostomatitis
HSV-2: Recurrrent genital herpes

Herpes labialis (lips cheeks, or nose) - more common in adults
HSV encephalitis

Question 2

How is herpes simplex transmitted

Answer 2

HSV-1: oro-genital sex
HSV-2: vaginal or anal sex

Transmission most commonly occurs due to asymptomatic but infectious viral shedding (more common with HSV-2 in the first 12 months)

Question 3

Describe primary infection with herpes simplex

Answer 3

first time HSV-1/2 is acquired with NO existing antibodies to either virus type

This is asymptomatic in the majority of people with HSV-2

Question 4

Describe the latent and lytic states of herpes simplex

Answer 4

HSV can exist in a latent and lytic state
During latency, infectious virions are not produced.
The latent state usually occurs in local sensory ganglia (trigeminal/sacral ganglia) where it persists lifelong

Lytic infection is characterised by viral replication and transport of the virus to the skin, with infection of skin and mucosal surfaces
Associated with HSV encephalitis

Question 5

What are the risk factors for herpes simplex infection

Answer 5

HIV infection
Immunosuppressive medication
High risk sexual behaviour (high number, unprotected, MSM)
Female sex
Black race
Increasing age (15-24 peak)
Lack of condom use

Question 6

What is the epidemiology for herpes simplex

Answer 6

35% of adults >60 are seropositive for HSV2

Infection most commonly acquired during childhood, and seropositivity increases with age
Prevalence of both types is higher among women

Question 7

What are the symptoms of genital herpes simplex infection

Answer 7

Prodrome: tingling/burning pain in the genital area, lower back, buttocks, or upper thighs 48h before

Multiple painful crops of genital blisters
- Quickly burst to leave erosions and ulcers on the external genitalia, perineum, and/or perianal region
- Typically develop 4-7 days after exposure to HSV infection
- Lasts up to 3 weeks

Dysuria
Vaginal or urethral discharge
Headache
Malaise
Fever

Question 8

What are the extra-genital manifestations of herpes simplex infection

Answer 8

HSV encephalitis (Usually HSV1)
Keratoconjunctivitis: Epiphoria (watering eyes), photophobia
Herpetic whitlow: vesicular lesions on the hands or digits e.g. thumb-sucking in children
Eczema herpeticum: extensive eruptions of herpes simplex in people with atopic eczema
Blepharitis conjunctivitis: May extend to involve the cornea → dendritic ulceration → corneal scarring → loss of vision
Herpes simplex meningitis
Immunocompromised: oral herpes infection - severe, atypical single/multiple necrotising lesions anywhere in the oral cavity, which may be large and persistent (usually long the vermilion border)

Question 9

What are the differentials for herpes simplex

Answer 9

Syphilis
Lymphogranuloma venerum (chlamydia)
Trichomoniasis
Herpes zoster
Fungal infection
Genital malignancy

Question 10

What are the signs of herpes simplex on examination

Answer 10

Pelvic exam
- Genital ulcer
—Multiple painful ulcers
— Vesicular lesions → ulceration → crusted lesions
—Bilateral with signs of redness, vesicles, blisters, and ulcers
— Lesions may also effect the vagina, cervix, buttocks, upper thighs
(Recurrent episodes: often unilateral and localised to a dermatome)

• Tender bilateral inguinal lymphadenopathy

Question 11

What investigations should be done for herpes simplex

Answer 11

Refer to GUM

Bedside:
- Viral swab of a popped fluid-filled blister for NAAT: +ve
- Viral swab “ for PCR: +ve
- Vulvovaginal swab: exclude chlamydia/gonorrhoea

Bloods
- HSV-1/HSV-2 serology (IgG): raised
- Western blot: diagnostic gold standard
- HIV serology
- Syphilis serology

Question 12

What is the management for herpes simplex virus

Answer 12

Refer to GUM
Self-limiting → supportive management

Hygiene and lifestyle advice
- Saline bath (1 teaspoon of salt in 560ml warm water)
- Analgesia e.g. paracetamol, ibuprofen
- Topical petroleum jelly
- Topical anaesthetic
- Increased fluid intake
- Avoid tight clothing
- Abstain from all sexual activity if lesions are present, resume when lesions have cleared
- Partners should be referred for screening

Primary/recurrent/gingivostomatitis
First line: oral aciclovir 3x daily (or valaciclovir, famciclovir)

Question 13

What are the red flags for admission for herpes simplex

Answer 13

Urinary retention
Meningism
Severe constitutional symptoms

Question 14

What are the complications of herpes simplex infection

Answer 14

Secondary infection of lesions with Candida or Streptococcus
Autoinoculation to fingers (herpetic whitlow), adjacent skin e.g. thighs or eyes
Balanitis
Progressive, multifocal, and coalescing mucocutaneous anogenital lesions
Urinary retention
Herpes retention
Systemic infection e.g. meningitis, encephalitis, fulminant hepatitis, pneumonitis

Question 15

What is the prognosis for genital herpes simplex

Answer 15

Ib most, a mild, self-limiting illness
Genital herpes is a chronic condition with variable frequency of recurrence
Some people will have frequent outbreaks, some remain asymptomatic
On average people have 4-5 recurrences a year following their first symptomatic episode
Symptoms typically reduce in severity and frequency
Pre-existing HSV-1 antibodies provide only partial protection against the acquisition of HSV-2

Question 16

Features of oral herpes simplex infection

Answer 16

Prodrome: fever, general malaise, sore throat

Vesicular lesions on the lips, gums, and anterior surfaces of the tongue and hard palate
- Grouped in crops
Progresses to extensive, painful ulceration with bleeding that crusts over and heals

Sore mouth/throat with excess salivation/drooling
Crops of painful vesicles on a red swollen base → ruptures and form ulcers on the pharyngeal and oral mucosa (palate, buccal mucosa, tongue, gingiva, and floor of the mouth)
Areas of ulceration may be covered by yellow/grey membranes.