Herpes

Definition

Herpes is a common viral sexually transmitted infection caused by Herpes Simplex Virus type 1 (HSV-1) and type 2 (HSV-2). It is characterized by recurrent painful vesicular lesions on the genital, perianal, and oral regions, with lifelong latency in sensory ganglia and periodic reactivation.

Symptoms of Herpes

Symptoms of herpes vary between primary and recurrent infections. Primary infection presents 2-12 days after exposure with multiple painful vesicular lesions on an erythematous base that rupture to form erosions and ulcers. Systemic symptoms include fever, headache, myalgia, and inguinal lymphadenopathy. Recurrent episodes are typically milder with fewer lesions and shorter duration. The frequency and severity of recurrences decrease over time. Asymptomatic viral shedding occurs intermittently and contributes to ongoing transmission.

Clinical Images

Transmission of Herpes

HSV is transmitted through direct contact with infected mucosal surfaces or skin, particularly during active lesion shedding. Most transmission occurs from individuals with unrecognized or subclinical infection who are shedding virus asymptomatically. HSV-2 is primarily sexually transmitted and causes genital herpes, while HSV-1 increasingly causes genital herpes through oral-genital contact. Neonatal herpes, acquired during delivery, is a rare but potentially fatal complication. Viral shedding is highest during active lesions but occurs even between outbreaks.

Incubation Period

Typical period: 2-12 days

The incubation period for primary herpes infection ranges from 2-12 days after exposure. Primary lesions typically appear within 4-7 days and can persist for 2-4 weeks. The virus then establishes lifelong latency in the sensory ganglia, with periodic reactivation triggered by factors such as stress, illness, immunosuppression, fever, and UV exposure.

Complications of Herpes

HSV infection can cause serious complications particularly in immunocompromised individuals. Aseptic meningitis and encephalitis are rare but severe neurological complications. Neonatal herpes occurs in 1 in 3,000-20,000 deliveries with high morbidity and mortality. HSV infection increases HIV risk by 2-4 fold through disruption of mucosal barriers. Eczema herpeticum is a disseminated infection in atopic dermatitis patients. Auto-inoculation can cause herpetic whitlow on fingers or ocular herpes with potential corneal scarring.

Treatment Options for Herpes

HSV infection is not curable, but antiviral therapy effectively manages symptoms and reduces transmission risk. Episodic treatment at the onset of recurrences shortens lesion duration. Suppressive therapy is recommended for patients with frequent recurrences and for serodiscordant couples to reduce transmission risk. All patients should be counseled about the natural history of the infection, the risk of asymptomatic shedding, and strategies to prevent transmission. Partner notification and testing should be offered.

Prevention of Herpes

Complete prevention of HSV transmission is challenging due to asymptomatic shedding. Condoms reduce but do not eliminate transmission risk. Suppressive antiviral therapy reduces transmission risk to susceptible partners by 50%. Disclosure of HSV status allows informed partner decision-making. There is no vaccine currently available. Avoidance of sexual activity during prodromal symptoms and active lesions reduces transmission risk. Pregnant women with recurrent genital herpes should be managed to prevent neonatal transmission.