Rosen & Barkin's 5-Minute Emergency Medicine Consult (343 page)

• Immunocompromise
  
• Disseminated disease
  
• HZO with cranial nerve involvement
  
• Intractable pain
  
• Isolation:
  
  • Airborne precautions for all patients with primary varicella or disseminated zoster, or immunocompromised patients with dermatomal zoster
    
  • Patients are infectious from 48 hr before appearance of rash until crusting of all lesions
    

• Most are managed as outpatients
  
• Patients should be instructed that lesions may heal with scarring or leave depigmented areas
  
• Recommend isolation from pregnant or immunocompromised persons until all lesions are crusted
  
• PHN may require long-term follow-up and/or referral to pain specialist
  

Usually treated as outpatients

Admit all neonates with zoster

• Look for ocular involvement if rash involves the tip of the nose (Hutchinson sign)
  
• Expose the skin of every patient with chest pain
  
• Failure to consider the diagnosis in the absence of rash
  
• Failure to warn patients of the risk of PHN
  

• Leung J., Harpaz R, Baughman AL, et al. Evaluation of laboratory methods for diagnosis of varicella.
  Clin Infect Dis.
  2010;51(1):23–32.
  
• Liesegang TJ. Herpes zoster ophthalmicus natural history, risk factors, clinical presentation, and morbidity.
  Ophthalmology
  . 2008;115:S3–S12.
  
• Opstelten W, Eekhof J, Neven AK, et al. Treatment of herpes zoster.
  Can Fam Physician
  . 2008;54:373–377.
  
• Oxman, M.N., Levin MJ, Johnson GR, et al. A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults.
  N Engl J Med.
  2005;352(22):2271–2284.
  
• Schmader KE, Dworkin RH. Natural history and treatment of herpes zoster.
  J Pain.
  2008;9(1 suppl 1):S3–S9.
  

CODES

• 053.9 Herpes zoster without mention of complication
  
• 053.29 Herpes zoster with other ophthalmic complications
  
• 053.71 Otitis externa due to herpes zoster
  

BASICS

• Genital herpes is a lifelong recurrent infection
  
• ∼1 in 4 Americans older than age 30 are seropositive for herpes simplex virus type 2 (HSV-2):
  
  • Most are asymptomatic
    
• 1st episode/primary HSV infection:
  
  • 2–12 day incubation
    
  • Symptoms peak 8–10 days after onset
    
  • Lesions heal in 3 wk
    
  • Primary infection may have more prominent clinical syndrome and complications (e.g., encephalitis, meningitis, hepatitis)
    
  • Primary infection may also go unnoticed:
    
    • >50% of 1st recognized signs and symptoms are not primary infection
      
• Recurrent HSV infection:
  
  • Average patient has 4 recurrences per year, by herpes simplex virus type 1 (HSV-1) recurs less than HSV-2
    
  • Virus reactivated from dorsal root ganglia
    
  • Triggered by local trauma, emotional stress, fever, sunlight, cold or heat, menstruation, or infection
    
  • Milder clinical syndrome and fewer lesions that usually heal within 10 days
    
• Asymptomatic HSV infection:
  
  • Virus is shed intermittently and often transmitted by persons who are without lesions or symptoms
    

• 70–90% caused by a DNA virus HSV-2:
  
  • Remainder caused by HSV-1
    
• Increasing prevalence of genital HSV-1 infection:
  
  • Higher rates of oral sex
    
  • Falling incidence of childhood (nonsexual) transmission owing to improved social conditions resulting in a larger pool of susceptible adolescents and adults
    
• Primary genital infection by HSV-1 is similar to HSV-2 in symptoms and duration, but recurs much less frequently
  
• Acquisition of HSV-2 in patients with pre-existing HSV-1 infection is less commonly associated with systemic symptoms:
  
  • Acquisition of HSV-1 in persons with pre-existing HSV-2 infection is rare
    
• HSV vaccines unsuccessful to date, research is ongoing
  
• High association with HIV and other STDs
  

DIAGNOSIS

• Local pain and itching
  
• Herpetic cervicitis, vaginitis, or urethritis may present with dysuria, urinary hesitance or retention, vaginal discharge, or pelvic pain
  
• Herpetic pharyngitis or gingivostomatitis may occur with oral acquisition
  
• Systemic symptoms like fever, headache, malaise, photophobia, anorexia, myalgias, and lymphadenopathy are more common with primary infection
  

• 1–2 day prodrome of local tingling, burning, itching, or pain prior to eruption (can mimic sciatica)
  
• Classically, lesions are noted on day 2 as macules and papules, then progress to vesicles, pustules, and then ulcerate by day 5
  
• Skin lesions crust over; mucosal membrane lesions heal without crusting
  

• Lesions on vulva, vagina, cervix, perineum, buttocks; penile shaft or glans
  
• Grouped vesicles on an erythematous base
  
• On moist mucosal surfaces, ulcers may predominate
  
• Atypical features may include localized edema, erythema, crusts, or fissures
  

• Neonatal infections are often disseminated or involve the CNS with high morbidity and mortality
  
• Congenital HSV in the neonate without vesicles may mimic rubella, cytomegalovirus (CMV), or toxoplasmosis
  
• Consider sexual abuse in children with genital HSV; culture lesions and test for other STDs in suspected cases
  

Diagnosis based on history and physical exam

• Viral load in lesions of primary infection are greater than those seen in recurrence
  
• Tzanck preparation and staining of fluid from lesions is insensitive and nonspecific
  
• Viral culture of vesicle fluid or ulcer base positive in 80–95% of cases, decreasing sensitivity as lesions crust and heal:
  
  • 3–10 days for result
    
• PCR 1.5–4 times more sensitive than viral culture; test of choice for CSF analysis in suspected CNS infection
  
• Serologic tests not helpful in acute disease:
  
  • Highly sensitive and specific; detect anti-gG1 and anti-gG2 antibodies
    
  • Require 2 wk to >3 mo to detect seroconversion
    
  • Cannot distinguish acute from chronic disease
    
  • HerpeSelect HSV-1/HSV-2 ELISA:
    
    • Takes hour to days in lab
      
  • POCkit HSV2, bedside results in 10 min
    

No imaging generally indicated

• Syphilis (Treponema pallidum)
  
• Chancroid (Haemophilus ducreyi)
  
• Lymphogranuloma venereum (LGV)
  
• Granuloma inguinale (Klebsiella granulomatis)
  
• Candidiasis
  
• Behcçet syndrome
  

TREATMENT

Universal precautions should be maintained

Rarely required unless associated with systemic symptoms requiring hospitalization:

• Disseminated infection
  
• Hepatitis
  
• Pneumonitis
  
• Meningoencephalitis
  

• Treatment partially controls symptoms and lesions; does not eradicate latent virus nor affect recurrences after drug is discontinued
  
• Episodic treatment of recurrences may shorten duration of lesions or ameliorate recurrences
  
• Daily suppressive therapy in patients with frequent recurrences (6 or more per year) reduces frequency of recurrences by 75%
  
• Famciclovir and valacyclovir are equally effective medications with less frequent dosing regimens, all interfere with viral DNA polymerase
  
• Resistance to acyclovir in immunocompromised individuals is 5–10%:
  
  • Foscarnet 40 mg/kg IV q8h may be effective
    
• Consider testing for concomitant STDs, those with an HSV outbreak are more likely to contract HIV
  
• Consider bladder catheterization, either indwelling or intermittent, for women with difficulty urinating due to possible sacral nerve involvement
  

• Women with primary HSV infection during pregnancy should receive antiviral therapy:
  
  • High rates of neonatal morbidity in both symptomatic and asymptomatic patients
    
• Suppressive antiviral therapy after 36 wk associated with decreased incidence of lesions at delivery:
  
  • Decreased cesarean delivery rates