Transcript All About Herpes Simplex Virus

Herpes
Dr. Meg-angela Christi Amores
Herpes Simplex
• Etiologic agent:
– Herpes Simplex Virus (HSV)
• DNA virus
• HSV 1 and HSV 2
Herpes Simplex
• Pathogenesis
– Exposure to HSV at mucosal surfaces or
abraded skin
– Entry of virus and replication in epid and
dermis
– sensory or autonomic nerve endings
– On entry into the neuronal cell, the virus—
or, more likely, the nucleocapsid—is
transported intra-axonally to the nerve cell
bodies in ganglia
– Contiguous spread of locally inoculated
virus
Herpes Simplex
• Immunity
– antibody-mediated and cell-mediated
– Immunocompromised patients with defects in
cell-mediated immunity experience more severe
and more extensive HSV infections
Clinical Spectrum
• clinical manifestations and course of HSV
infection depend on the anatomic site
involved, the age and immune status of the
host, and the antigenic type of the virus
• incubation period ranges from 1 to 26 days
(median, 6–8 days)
• Both viral subtypes can cause genital and oralfacial infections
Oral-facial Infection
• Gingivostomatitis and pharyngitis
– most common clinical manifestations of
first-episode HSV-1 infection
– among children and young adults
– fever, malaise, myalgias, inability to eat,
irritability, and cervical adenopathy,
may last 3–14 days
– Lesions may involve the hard and soft
palate, gingiva, tongue, lip, and facial
area
Oral-Facial Infection
• recurrent herpes labialis
– most common clinical manifestation of
reactivation HSV-1 infection
• HSV-1 and varicella-zoster virus (VZV) have
been implicated in the etiology of Bell's palsy
(flaccid paralysis of the mandibular portion of
the facial nerve).
Genital Infection
• First episode:
– fever, headache, malaise, and myalgias
– Pain, itching, dysuria, vaginal and urethral
discharge, and tender inguinal lymphadenopathy
– Widely spaced bilateral lesions of the external
genitalia
– Lesions varied: vesicles, pustules, or painful
erythematous ulcers
– HSV2 recurs more
Genital Infection
• Both HSV-1 and HSV-2 can cause symptomatic
or asymptomatic rectal and perianal
infections.
• subclinical perianal shedding of HSV is
detected in women and men who report no
rectal intercourse
• anorectal pain, anorectal discharge, tenesmus,
and constipation
Other areas
• Herpetic whitlow—HSV infection of the finger
– may occur as a complication of primary oral or
genital herpes by inoculation of virus or
– direct introduction of virus into the hand through
occupational or some other type of exposure
– abrupt-onset edema, erythema, and localized
tenderness of the infected finger
– Vesicular or pustular lesions of the fingertip
– Fever, lymphadenitis, and epitrochlear and axillary
lymphadenopathy
Other areas
• Herpes gladiatorum
– Common among wrestlers
– HSV infections of the thorax, ears, face, and hands
– facilitated by trauma to the skin sustained during
wrestling
Other areas
• Eye Infection
– most common cause of corneal blindness in the
United States
– acute onset of pain, blurred vision, chemosis,
conjunctivitis, and characteristic dendritic lesions
of the cornea
• Central and Peripheral Nervous System
infections
– accounts for 10–20% of all cases of sporadic viral
encephalitis
Management
• Diagnosis
– clinical and laboratory
– characteristic multiple vesicular lesions on an
erythematous base
– detection of virus, viral antigen, or viral DNA
– PCR
Management
• Treatment
– mucocutaneous infections: Acyclovir
– topical use in HSV eye infections: idoxuridine,
trifluorothymidine, topical vidarabine, and
cidofovir
– encephalitis and neonatal herpes, IV acyclovir
Management
• Acyclovir is the agent most frequently used for
the treatment of HSV infections and is
available in IV, oral, and topical formulations.
• acyclovir, valacyclovir, and famciclovir
– effective in shortening the duration of symptoms
and lesions of mucocutaneous HSV infections
Management
• Prevention
– Barrier forms of contraception (especially
condoms) decrease the likelihood of transmission
of HSV infection
– When lesions are present, HSV infection may be
transmitted by skin-to-skin contact despite the
use of a condom