Herpes simplex virus (I)

Question 1

What are the two strains of HSV in humans?

Answer 1

HSV-1 and HSV-2

Question 2

How is HSV transmitted?

Answer 2

Via direct contact with mucosal tissue or secretions of another infected person

Portal of entry:

• mucosal surfaces
• skin breaks
• vertical transmission during pregnancy / childbirth through infected vagina

Question 3

How is HSV-1 usually acquired?

Answer 3

In childhood via saliva

Question 4

How is HSV-2 usually spread?

Answer 4

Through genital contact

Question 5

What diseases does HSV-1 vs HSV-2 cause? (2 + 1)

Answer 5

• HSV-1: herpes labialis i.e. cold sores (oral herpes), HSV encephalitis, (genital herpes)
• HSV-2: genital herpes

Question 6

Describe the pathophysiology of HSV.

Answer 6

• replicates in epidermis –> travels down nerve endings + axons –> virus lives in sensory ganglia of face (trigeminal ganglia) + genitalia (sacral nuclei)
• latent cycle where periodic reactivation when illness/trigger
• virus becomes active in ganglia –> transported via axon to skin + replicates in epidermis –> sheds –> new sores
• often asymptomatic shedding - may feel tingling and burning before blisters

Question 7

What is herpes labialis (oral herpes) associated with?

Answer 7

Infection of mouth and lips, associated with HSV-1

Question 8

What is genital herpes associated with?

Answer 8

HSV-1 or HSV-2

Question 9

What are the major clinical manifestations of infection with HSV? (3)

Answer 9

• oral (herpes labialis)
• genital
• ocular ulcers

Question 10

What are some risk factors for HSV infection? (5)

Answer 10

• HIV
• immunosuppressive medications
• high-risk sexual behaviour
• contact with infected individual
• wrestlers

Question 11

What are the clinical features of herpes labialis (oral herpes)? (6)

Answer 11

• painful ulcers around mouth
• high fever
• sore throat - pharyngeal oedema
• myalgia
• cervical lymphadenopathy
• recurrent infection - pain, burning, tingling, vesicle formation

Question 12

What are the clinical features of genital herpes? (7)

Answer 12

• genital ulcers/vesicles
• genital pain
• dysuria
• fever
• neuralgia
• pruritus
• GI symptoms - constipation, rectal pain, tenesmus, proctitis

Question 13

How might HSV affect the eyes?

Answer 13

Keratoconjunctivitis

Question 14

How might HSV affect the CNS?

Answer 14

Meningitis / encephalitis typically affecting the temporal lobe

Question 15

How might the primary infection of HSV present?

Answer 15

May present with a severe gingivostomatitis (erythema and painful ulcerations on perioral skin and oral mucosa)

Question 16

What is eczema herpeticum (HSV)?

Answer 16

• potentially life threatening severe primary infection of the skin by HSV-1 or HSV-2
• commonly seen in children with atopic eczema
• rapidly progressing painful rash with punched out erosions
• Rx: IV acyclovir

Question 17

How does herpes simplex keratitis present? (4)

Answer 17

• red painful eye
• photophobia
• epiphora (watery eye)
• fluorescein staining shows linear branching epithelial ulcer

Question 18

What are the first-line investigations for HSV? (3)

Answer 18

• HSV PCR
• viral culture
• glycoprotein G-based type-specific serology (gG1 and gG2)

Question 19

What do we order when HSV lesions are present?

Answer 19

• viral PCR
• viral culture to detect type of virus
• suspected genital herpes –> nucleic acid amplification tests (NAAT) - after obtaining swab at base of ulcer

Question 20

What are some differential diagnoses for HSV/herpes? (10)

Answer 20

• syphilis (non-tender ulcer, Treponema pallidum)
• chancroid (single deep painful ulcer)
• lymphogranuloma venerum
• contact dermatitis
• Behcet’s disease
• Crohn’s disease / ulcerative colitis
• scabies
• fixed drug eruption
• squamous cell carcinoma
• shingles on buttocks/lower extremities/periorally

Question 21

What is the general first-line treatment for HSV infection?

Answer 21

Oral acyclovir

Question 22

What do we give for symptom relief in HSV infection? (5)

Answer 22

• IV fluids
• barrier creams
• pain relief
• antipyretics
• Abx

Question 23

How do we manage a pregnant woman during 3rd trimester with genital herpes?

Answer 23

Oral acyclovir until delivery and do C-section (not vaginal delivery) - if primary attack after 28wk gestation

Recurrent herpes - suppressive therapy

Question 24

What is 1st-line for HSV if pneumonitis, hepatitis, encephalitis or meningitis?

Answer 24

IV acyclovir

Question 25

What is 1st-line for HSV if gingivomatitis?

Answer 25

Oral acyclovir + chlorhexidine mouthwash

Question 26

What is 1st-line for HSV if cold sores (oral herpes)?

Answer 26

Topical acyclovir

Question 27

What is 1st-line for HSV if genital herpes?

Answer 27

• 1st-line: oral acyclovir / valacyclovir / famciclovir
• PLUS paracetamol/ibuprofen/lidocaine
• 2nd-line: foscarnet
• longer term acyclovir for those with frequent exacerbation

Question 28

What are some complications of HSV infection? (10)

Answer 28

• oesophagitis
• meningitis
• encephalitis
• hepatitis
• Bell’s palsy
• uveitis
• keratitis
• erythema multiforme
• acute renal necrosis
• neonatal HSV: lesion, seizures, sepsis

Question 29

Describe the prognosis of HSV infection.

Answer 29

• genital and oral herpes are chronic viral infections with a highly variable course
• some may have frequent outbreaks whereas others will be completely asymptomatic