Snapshot A 20-year-old college student presents to the student health clinic complaining of a painful, blistering rash on her upper lip. She says the rash has relapsed and remitted multiple times and she usually feels a mild tingling sensation in the area before a break-out of the lesions. On exam, her upper lip demonstrates clustered vesicles with an erythematous base and crusting. Introduction Overview herpes simplex is highly-transmissible viral infection of the skin characterized by painful, recurrent vesicular eruptions of the mucocutaneous surfaces may occur orally or genitally prodromal symptoms such as tingling may occur prior to outbreaks treatment with acyclovir or valacyclovir for bothersome symptoms to prevent transmission to a serodiscordant sex partner Associated conditions HIV gonorrhea chlamydia herpes encephalitis Bell palsy Epidemiology Prevalence high rates of infection in the general population prevalence of HSV-1 is almost 50% amongst U.S. adults prevalence of HSV-2 is around 12% amongst U.S. adults almost 80% of infected persons are asymptomatic Demographics occurs in sexually active teenagers and adults oral infection also commonly occurs in early childhood transmission from relatives through kissing or sharing utensils if child has genital disease, must rule out sexual abuse almost two times more common in women than men Location lesions of either viral type may occur on the mouth or genitals HSV-1 is more commonly found in oral infections HSV-2 is more commonly found with genital infections Risk factors sex with an infected person many sex partners condomless sex transmission can still occur when using barrier protection HIV infection or immunosuppression first sexual intercourse at a young age history of STIs ETIOLOGY Pathogenesis caused by two major strains of the Herpes simplex virus (HSV) HSV-1 oral-labial form HSV-2 genital form Transmission occurs from direct contact with active lesions Virus resides in the dorsal root ganglia of local nerves until reactivation mechanism for recurrence is not well-understood immunosuppression plays a role Intrahost viral spread occurs via epidermal cells subsequent abnormal cell division creates multinucleated "giant cells" Presentation Symptoms common symptoms painful genital or oral burning vesicular eruptions with crusting tingling prodrome primary genital infection painful inguinal lymphadenopathy fever malaise primary oral infection gingivitis oral ulcers cervical lymphadenopathy location upper or lower lip of the mouth labia, vagina, vulva, cervix penis anus cutaneous lesion on the hand (herpetic whitlow) eye (herpetic keratitis) duration incubation period 2-12 days first outbreak may last 2-3 weeks subsequent outbreaks may clear after 2-7 days severity often asymptomatic primary eruption is most severe severity decreases over time aggravating factors psychological stress fatigue menstruation sunglight exposure illness alleviating factors medication Physical exam inspection many infections present with grouped vesicles on an erythematous base genital infection often presents with pedunculate papule bilateral, erosive vesicles on the genitals recurrence typically unilateral oral infection primary infection severe, widespread gingivostomatitis and oral erosions recurrence common "cold sore" herpetic whitlow cutaneous lesion on the hand that can be caused by HSV-1 or HSV-2 most commonly seen in health care workers who come in contact with oral secretions (respiratory therapists, dentists) Studies Tzanck smear useful for presumptive diagnosis multinucleated giant cells acantholytic cells Culture or direct fluorecent anti-body staining can be used to distinguish betwen Varicella zoster and Herpes due to similar findings on Tzanck smear Differential Herpes zoster virus key disgintuishing factor (HZV) dermatomal distribution of vesicles Varicella zoster virus (VZV) key distinguishing factors vesiculopustular lesions primarily on face, trunk, and scalp Treatment Lifestyle avoid sunlight reduce stress Medical acyclovir (oral or IV) indicated as mainstay of treatment both decreases frequency and severity of recurrences side effects may be nephrotoxic prevent/treat nephrotoxicity with IV fluids acyclovir ointment may be indicated as adjunct to first line therapy effective in reducing duration of viral shedding does not prevent recurrence acyclovir or valacyclovir suppresive therapy indicated only in patients with >6 breakouts per year or with erythema multiforme acyclovir taken daily Complications Complications HSV encephalitis incidence 2-4/1,000,000 risk factors immunosuppression older age young children treatment IV acyclovir Prognosis No cure Relapsing and remitting course symptoms become less severe over time Treatment can improve symptoms