Introduction
Background
The herpes simplex viruses comprise 2 distinct types of DNA viruses: herpes simplex virus 1 (HSV-1) and herpes simplex virus 2 (HSV-2). The epidemiology of herpes infection has dramatically changed over the past several decades.1 HSV-1 causes oral lesions in approximately 80% of cases and genital lesions in 20% of cases. In adolescents, as many as 30-40% of genital herpes is caused by HSV-1, as this proportion is thought to be increasing in the developed world, due to increased oro-genital contact. The reverse is true for HSV-2, which causes genital lesions in 80% and oral lesions in 20%.
Approximately 65% of the United States population is seropositive for HSV-1 by the fourth decade of life. Approximately 25% of the United States population is seropositive for HSV-2 by the fourth decade of life, with women being infected more frequently than men.1 The indirect and direct costs of incident HSV genital infection in the United States are presently approximately $1.8 billion and expected to be greater than $2.7 billion by the year 2015.
Herpes viruses cause a wide range of diseases, including the following:
- Gingivostomatitis
- Keratoconjunctivitis
- Encephalitis
- Genital disease
- Newborn infection
Primary infection
Primary infections usually are mild and, in many cases, asymptomatic. Patients who are immunocompromised may develop severe infections involving multiple organ systems. Immunocompetent individuals also may have severe primary infections.
Latency and recurrence
After the patient begins to produce antibodies, the infection becomes latent in the sensory ganglia. HSV-1 infection remains latent in the trigeminal ganglia and HSV-2 in the sacral ganglia. The viruses become reactivated secondary to certain stimuli, including fever, physical or emotional stress, ultraviolet light exposure, and axonal injury.
Recurrent infections tend to be less severe because of existing cellular and humoral immunity from prior exposures. Although many persons are seropositive for HSV-1, the recurrence rates range from 10-40% after the primary infection. Infection by HSV requires a break in the skin's barrier; intact skin is resistant to the virus.
Pathophysiology
HSV-1 infections are spread via respiratory droplets or direct exposure to infected saliva. HSV-2 usually is transmitted via genital contact. The contact must involve mucous membranes or open or damaged skin. The incubation period may last from 2-12 days, and vesicles typically erupt 6-48 hours after the onset of a prodrome.
Herpes viruses cause cytolytic infections; therefore, pathologic changes are due to cell necrosis as well as inflammatory changes. Fluid accumulates between the dermis and the epidermal skin layers, causing vesicle formation. The fluid then is absorbed, scabs are formed, and healing is completed without evidence of scarring. Shallow ulcers form after the vesicles rupture on mucous membranes.
Lesions from primary herpes infection typically take longer to form and usually persist for a longer duration of time.
The virus travels from the site of infection in the skin or mucosa to the sensory dorsal root and remains latent until a recurrent outbreak. Outbreaks are usually due to some sort of stress including ultraviolet radiation, trauma, emotional or psychological stress, or immunosuppression.
Frequency
United States
Approximately 80% of adults have antibodies to HSV-1, whereas antibodies to HSV-2 are found in approximately 20% of the population.
- The incidence of genital herpes has been estimated to be 500,000-1,000,000 cases per year with a prevalence of 40-60 million affected individuals.
- In sexually transmitted disease (STD) clinics, HSV-2 seropositivity approaches 40-50%.
- Encephalitis develops in 1 per 250,000-500,000 patients per year.
- Neonatal HSV develops in 1 per 2,000-10,000 live births per year. Approximately 70% of cases of neonatal HSV occur when the mother is asymptomatically shedding virus near time of delivery. The risk of neonatal transmission is increased if vaginal delivery occurs during acute maternal infection.
- Approximately 90% of HIV-positive individuals are seropositive for HSV-1, and about 77% of HIV-positive individuals are seropositive for HSV-2.
International
Greater than one third the world's population has recurrent clinical HSV infections. Reportedly, 13-40% of the world's population is seropositive for HSV-2 and 56-85% is seropositive for HSV-1, varying by country.
Mortality/Morbidity
Most patients with herpetic infection experience short-term local pain and irritation, with mild constitutional symptoms.
- Infection occasionally may become life threatening.
- Immunocompromised patients are at increased risk of developing severe HSV infections.
- HSV-1 is a common cause of fatal encephalitis in the US, with a mortality rate 60-80%. Fewer than 10% of patients are left without significant neurologic sequelae.
- Keratoconjunctivitis may be caused by HSV-1. It is second only to trauma as a cause of corneal blindness in the US.
Race
African Americans are more likely to be infected with HSV-2 than any other racial or ethnic group.2 HSV-2 antibodies are present in approximately 20% of Caucasian adults and 65% of African American adults. Some experts consider nonwhite race as a risk factor to contract genital HSV-2.
Sex
Men are 20% more likely to develop recurrences of HSV-2 than are women.
Age
- Highest incidence of HSV-1 occurs in children aged 6 months to 3 years.
- HSV-2 most commonly occurs in those aged 18-25 years.
Clinical
History
The typical incubation period from exposure to development of symptoms is 4 days but can range from 1-26 days. Prodromal symptoms of local pain, tingling, itching, and burning often precede development of the rash. Constitutional symptoms of fever, fatigue, myalgias, and headache often accompany the primary herpes simplex virus (HSV) infection.
Herpetic lesions usually begin as clusters of small bumps, then blisters, followed by open sores or ulcers. Lesions coalesce and usually heal over several weeks.
Many times these classically described lesions in the genital area may not present in all patients and may be difficult to differentiate from other conditions such as syphilis and chancroid.
Local pain is a prominent and common complaint. Patients with genital herpes may also complain of pain in the groin area secondary to local adenopathy. Women often present with complaints of genital swelling, discharge, and dysuria.
- Many primary infections are asymptomatic. Up to 80% of women with HSV-2 antibodies have no clinical history of infection. However, when primary infections are symptomatic, they are usually more severe than recurrent infections.
- Recurrent lesions are common.
- Patients may give a history that includes the following:
- Occupational exposure
- Herpetic whitlow, found in health care workers (especially medical or dental)
- Herpes gladiatorum on bodies of wrestlers
- Previous history of herpetic diseases
- Apparently undiagnosed episodes
- Occupational exposure
- Immune status
- HIV
- Malnourishment
- Hematological malignancies
- Bone marrow
- Renal transplant
- Cardiac transplant
- Neurologic symptoms
- Headache
- Confusion
- Fever
- Lesions
- Location varies
- May be very painful
- Tenesmus, itching with anal/perianal lesions
- Dysuria with genital lesions
- Sore throat with oral lesions
- Constitutional symptoms (usually present with development of herpes lesions)
- Anorexia
- General malaise
- Fever
- Headache
- Myalgias
- Prodromal symptoms (present in advance of herpes lesions)
- Burning
- Itching
- Tingling
- Pain
Physical
Physical examination findings of HSV vary depending on location of the lesions.
- General findings
- Lesions usually are vesicular or ulcerative on an erythematous base, as shown in the image below.
Cutaneous vesicles characteristic of herpes simples virus infection
- Lesions coalesce and then heal over the next several weeks.
- Tender bilateral lymphadenopathy occurs with genital lesions.
- Skin infections (HSV-1 or HSV-2)
- Herpetic whitlow or paronychia on the fingers of health care workers (not to be confused with abscess). This is usually is due to infection with HSV-1, but HSV-2 infections may be seen with digital-genital contact.
- Herpes gladiatorum on the bodies of wrestlers and other sports that involve close physical contact. It has been estimated that in Division I National Collegiate Athletic Association (NCAA) wrestling, the incidence of herpes gladiatorum can be as high as 20-40%.
- Oropharyngeal disease
- Gingivostomatitis (herpes labialis on the lips, shown in the image below)
Herpes labialis
- Submandibular lymphadenopathy
- Fever
- Genital herpes
- Painful vesicular or ulcerative lesions may appear similar to chancroid or syphilis (vesicular lesions shown in the image below)
Penile infection with herpes simplex virus type 2
- Inguinal lymphadenopathy
- Genital lesions, especially urethral lesions, may cause transient urinary retention in women
- Keratoconjunctivitis
- Dendritic keratitis found with slit lamp (dendritic ulcer shown in the image below)
Herpes simplex virus dendritic ulcer with fluorescein staining.
- Corneal ulcers
- Vesicles on eyelids
- Neurologic
- New psychiatric symptoms (indicative of encephalitis)
- Confusion
- Seizures
- Meningeal signs - Recurrent lymphocytic meningitis (benign form of meningitis/encephalitis that may occur during primary HSV-2 infection)
- Bell palsy (possible relationship with HSV-1)
- New psychiatric symptoms (indicative of encephalitis)
- Anal/perianal involvement
- Discharge
- Vesicles
- Ulcerations
- Inguinal adenopathy
Causes
- HSV-1 - Transmitted through direct contact with infected saliva or direct contact with contaminated utensils
- HSV-2 - Usually acquired as an STD
- Maternal-fetal transmission-risk of transmission is greater in primary outbreak (30-50%) than with recurrent outbreaks (<1%)2
- Recurrent disease (reactivation) due to certain stimuli
- Fever
- Physical or emotional stress
- Ultraviolet light exposure
- Axonal injury
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| References |
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References
Mell HK. Management of oral and genital herpes in the emergency department. Emerg Med Clin North Am. May 2008;26(2):457-73, x. [Medline].
Biggs WS, Williams RM. Common gynecologic infections. Prim Care. Mar 2009;36(1):33-51, viii. [Medline].
[Guideline] Workowski KA, Berman SM. Sexually transmitted diseases treatment guidelines, 2006. MMWR Recomm Rep. Aug 4 2006;55:1-94. [Medline].
Frenkl TL, Potts J. Sexually transmitted infections. Urol Clin North Am. Feb 2008;35(1):33-46; vi. [Medline].
Benedetti J, Corey L, Ashley R. Recurrence rates in genital herpes after symptomatic first-episode infection. Ann Intern Med. Dec 1 1994;121(11):847-54. [Medline].
Clark JL, Tatum NO, Noble SL. Management of genital herpes. Am Fam Physician. Jan 1995;51(1):175-82, 187-8. [Medline].
Cockerell C. Diagnosis and treatment of cutaneous herpes simplex virus infections. West J Med. Jun 1996;164(6):518-20. [Medline].
Hill J, Roberts S. Herpes simplex virus in pregnancy: new concepts in prevention and management. Clin Perinatol. Sep 2005;32(3):657-70. [Medline].
Hirsch MS. Herpes simplex virus. In: Mandell GL, ed. Mandell, Douglas, and Bennet's Principles and Practice of Infectious Diseases. 4th ed. Churchill Livingstone; 1995:1336-45.
Holland-Hall C. Sexually transmitted infections: screening, syndromes, and symptoms. Prim Care. Jun 2006;33(2):433-54. [Medline].
Johnson R. Herpes gladiatorum and other skin diseases. Clin Sports Med. Jul 2004;23(3):473-84, x. [Medline].
Patel R, Rompalo A. Managing patients with genital herpes and their sexual partners. Infect Dis Clin North Am. Jun 2005;19(2):427-38, x. [Medline].
Rooney JF, Straus SE, Mannix ML. Oral acyclovir to suppress frequently recurrent herpes labialis. A double-blind, placebo-controlled trial. Ann Intern Med. Feb 15 1993;118(4):268-72. [Medline].
Whitley RJ, Gnann JW Jr. Acyclovir: a decade later. N Engl J Med. Sep 10 1992;327(11):782-9. [Medline].
Wu JJ, Pang KR, Huang DB. Advances in antiviral therapy. Dermatol Clin. Apr 2005;23(2):313-22. [Medline].
Further Reading
Keywords
herpes simplex, herpes virus symptoms, herpes virus causes, herpes virus treatment, antivirals, herpes virus, HSV-1, HSV-2, oral lesions, genital lesions, herpes labialis, keratoconjunctivitis, newborn infection, neonatal HSV, sexually transmitted disease, STD, herpetic whitlow, herpes gladiatorum, herpetic diseases
