Herpes simplex virus (I) Flashcards
What are the two strains of HSV in humans?
HSV-1 and HSV-2
How is HSV transmitted?
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
How is HSV-1 usually acquired?
In childhood via saliva
How is HSV-2 usually spread?
Through genital contact
What diseases does HSV-1 vs HSV-2 cause? (2 + 1)
- HSV-1: herpes labialis i.e. cold sores (oral herpes), HSV encephalitis, (genital herpes)
- HSV-2: genital herpes
Describe the pathophysiology of HSV.
- 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
What is herpes labialis (oral herpes) associated with?
Infection of mouth and lips, associated with HSV-1
What is genital herpes associated with?
HSV-1 or HSV-2
What are the major clinical manifestations of infection with HSV? (3)
- oral (herpes labialis)
- genital
- ocular ulcers
What are some risk factors for HSV infection? (5)
- HIV
- immunosuppressive medications
- high-risk sexual behaviour
- contact with infected individual
- wrestlers
What are the clinical features of herpes labialis (oral herpes)? (6)
- painful ulcers around mouth
- high fever
- sore throat - pharyngeal oedema
- myalgia
- cervical lymphadenopathy
- recurrent infection - pain, burning, tingling, vesicle formation
What are the clinical features of genital herpes? (7)
- genital ulcers/vesicles
- genital pain
- dysuria
- fever
- neuralgia
- pruritus
- GI symptoms - constipation, rectal pain, tenesmus, proctitis
How might HSV affect the eyes?
Keratoconjunctivitis
How might HSV affect the CNS?
Meningitis / encephalitis typically affecting the temporal lobe
How might the primary infection of HSV present?
May present with a severe gingivostomatitis (erythema and painful ulcerations on perioral skin and oral mucosa)
What is eczema herpeticum (HSV)?
- 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
How does herpes simplex keratitis present? (4)
- red painful eye
- photophobia
- epiphora (watery eye)
- fluorescein staining shows linear branching epithelial ulcer
What are the first-line investigations for HSV? (3)
- HSV PCR
- viral culture
- glycoprotein G-based type-specific serology (gG1 and gG2)
What do we order when HSV lesions are present?
- viral PCR
- viral culture to detect type of virus
- suspected genital herpes –> nucleic acid amplification tests (NAAT) - after obtaining swab at base of ulcer
What are some differential diagnoses for HSV/herpes? (10)
- 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
What is the general first-line treatment for HSV infection?
Oral acyclovir
What do we give for symptom relief in HSV infection? (5)
- IV fluids
- barrier creams
- pain relief
- antipyretics
- Abx
How do we manage a pregnant woman during 3rd trimester with genital herpes?
Oral acyclovir until delivery and do C-section (not vaginal delivery) - if primary attack after 28wk gestation
Recurrent herpes - suppressive therapy
What is 1st-line for HSV if pneumonitis, hepatitis, encephalitis or meningitis?
IV acyclovir
What is 1st-line for HSV if gingivomatitis?
Oral acyclovir + chlorhexidine mouthwash
What is 1st-line for HSV if cold sores (oral herpes)?
Topical acyclovir
What is 1st-line for HSV if genital herpes?
- 1st-line: oral acyclovir / valacyclovir / famciclovir
- PLUS paracetamol/ibuprofen/lidocaine
- 2nd-line: foscarnet
- longer term acyclovir for those with frequent exacerbation
What are some complications of HSV infection? (10)
- oesophagitis
- meningitis
- encephalitis
- hepatitis
- Bell’s palsy
- uveitis
- keratitis
- erythema multiforme
- acute renal necrosis
- neonatal HSV: lesion, seizures, sepsis
Describe the prognosis of HSV infection.
- genital and oral herpes are chronic viral infections with a highly variable course
- some may have frequent outbreaks whereas others will be completely asymptomatic
