Herpes Simplex Virus

Question 1

Definition

Answer 1

Disease resulting from HSV1 or HSV2 infection

Question 2

Aetiology

Answer 2

Transmitted via close contact (e.g. kissing, sexual intercourse) with an individual that is shedding the virus

Question 3

Pathophysiology

Answer 3

o After primary infection, the virus will become dormant (within nerve ganglia)

o Reactivation may occur in response to physical and emotional stresses or immunosuppression

o The virus causes cytolysis of infected epithelial cells leading to vesicle formation

Question 4

Epidemiology

Answer 4

· 90% of adults are seropositive for HSV1 by 30 yrs

· 35% of adults > 60 yrs are seropositive for HSV2

· More than 1/3 of the world population have recurrent HSV infections

Question 5

Presenting symptoms (HSV 1)

Answer 5

· HSV1 - primary infection is often asymptomatic

· Possible symptoms of primary HSV1 infection:
o Pharyngitis
o Gingivostomatitis (eating might be painful)
o Herpetic whitlow (abscess at the end of the finger caused by infection with HSV - it is very painful)

· Symptoms of reactivation of HSV1:
o Prodrome of perioral tingling and burning
o Vesicles appear - they will ulcerate and crust over
o Complete healing within 8-10 days

Question 6

Presenting symptoms (other)

Answer 6

· Symptoms of HSV2:
o Painful blisters and rash in the genital, perigenital and anal area
o Dysuria
o Fever
o Malaise

· Symptoms of HSV encephalitis:
o Usually caused by HSV1 so causes HSV1 type symptoms

· Symptoms of HSV keratoconjunctivitis
o Watering eyes
o Photophobia

Question 7

Signs on physical examination

Answer 7

· HSV1 Primary Infection
o Tender cervical lymphadenopathy
o Erythematous, oedematous pharynx
o Oral ulcers filled with yellow slough (gingivostomatitis)
o Herpetic whitlow

· Herpes Labialis (reactivation affecting the mouth)
o Perioral vesicles/ulcers/crusting

· HSV2
o Maculopapular rash
o Vesicles
o Ulcers
o All of these are found on the external genitalia, anal margin and upper thighs
o Others: inguinal lymphadenopathy, pyrexia

· HSV2 Encephalitis
o Signs of encephalitis

· HSV Keratoconjunctivitis
o Dendritic ulcer on the iris (better visualised with fluorescein)

Question 8

Investigations

Answer 8

· Diagnosis is usually CLINICAL

· Vesicle fluid can be sampled and sent for electron microscopy, PCR