Infection: Herpes Simplex Virus Infections Flashcards
How many human herpes viruses are there?
Currently 8 known: Herpes simplex virus 1 (HSV-1) Herpes simplex virus 2 (HSV-2) VZV (chickenpox) CMV EBV (glandular fever) Human herpes virus 6 (HHV-6) Human herpes virus 7 (HHV-7) Human herpes virus 8 (HHV-8) - associated with Kaposi sarcoma in HIV infected individuals
What is the hallmark of most herpesviruses?
After primary infection, latency is established and there is long term persistence of virus within host - usually in dormant state. After certain stimuli, reactivation can occur
How does HSV usually enter the body?
Through mucous membranes or skin - site of primary infection may be associated with local mucosal damage
HSV1 is usually associated with what lesions?
Lip and skin
HSV2 is usually associated with what lesions?
Genital lesions
Are herpes simplex viruses mostly asymptomatic?
Yes
What is the most common form of primary HSV illness in children?
Gingivostomatitis
Describe the lesions seen in gingivostomatitis
Vesicular lesions
On lips, gums, anterior tongue and hard palate
Often progress to extensive, painful ulceration with bleeding
What other symptoms occur with gingivostomatitis (other than the vesicles)?
High fever
Child irritable
Pain on eating and drinking - may lead to dehydration
What age is typically affected with gingivostomatitis?
10 months to 3 years
How is gingivostomatitis treated?
Oral or IV acyclovir
Analgesia and fluids (oral or IV)
What are cold sores?
Recurrent HSV lesions on gingival/lip margin
What is eczema herpeticum?
Most often seen as a complication of atopic dermatitis
Widespread vesicular lesions develop on ezematous skin
Usually arises during first episode of infection with HSV1/2
What are the clinical features of eczema herpeticum?
Clusters of itchy vesicles and blisters than are painful
Most often seen on face and neck
May be filled with clear yellow fluid or purulent material, often blood stained
New blisters have central umbilication
Older blisters crust over and cause sores
Also: fever, malaise, lymphadenopathy
Eczema herpeticum can be complicated by…
Secondary bacterial infection, which may result in sepsis
Scarring
Herpetic keratitis - in children tends to be more severe
Organ failure and dissemination - particularly brain, lungs, liver
How should eczema herpeticum be managed?
Prompt treatment with anti viral medication
Aciclovir oral 400-800mg 5 times daily
How can HSV cause eye disease?
Blepharitis
Conjunctivitis
Dendritic ulcers - if involving cornea (herpes keratitis)
Any child with herpetic lesions near or involving eye require…
Urgent ophthalmic assessment - examination or cornea via slit lamp
Primary infection with HSV usually occur in childhood, then the virus lies dormant in which ganglion usually?
Trigeminal - can reactivate and travel along branches to cause infection
Is neonatal HSV common?
No
What are herpetic whitlows?
Painful, erythematous, oedematous white pustules on the site of broken skin, typically fingers.
Spread by autoinoculation from gingivostomatitis and infected adults kissing child’s fingers
How is neonatal herpes simplex virus transmitted?
During passage through infected birth canal or occasionally ascending infection
How does neonatal HSV present?
Localised lesions on skin or eye
Encephalitis
Disseminated disease
If eczema herpeticum is not diagnosed and treated promptly, what can it lead to?
Encephalitis
Blindness
Multi organ failure
What symptoms suggest HSV has spread to the eye?
Redness Pain Foreign body sensation Photophobia Tearing Decreased visual acuity
How can viral infection be confirmed?
PCR
Viral culture
Direct fluorescent antibody stain
If impetigo suspected a positive skin surface bacterial culture for staphylococcus or streptococcus does not exclude eczema herpeticum and is a common finding
Differentials of eczema herpeticum include…
Impetigo (differences= honey coloured crusting, no punched out ulcers)
Chickenpox (differences= pruritis and no punched out ulcers)
Cellulitis
Eczema molluscatum
Pustular psoriasis
