Herpes Simplex

A recurrent viral infection, herpes simplex is caused by Herpesvirus hominis (HVH), a widespread infectious agent. Herpes Type I, which is transmitted by oral and respiratory secretions, affects the skin and mucous membranes and commonly produces cold sores and fever blisters.

Herpes Type 2 primarily affects the genital area and is transmitted by sexual contact. Cross-infection may result from orogenital sex.

Causes

About 85% of all HVH infections are subclinical. The others produce localized lesions and systemic reactions. After the first infection, a patient is a carrier susceptible to recurrent infections, which may be provoked by fever, menses, stress, heat, and cold. In recurrent infections, the patient usually has no constitutional signs and symptoms.

Incidence

Primary HVH is the leading cause of gingivostomatitis in children ages 1 to 3. It causes the most common nonepidemic encephalitis and is the second most common viral infection in pregnant women. It can pass to the fetus transplacentally and, in early pregnancy, may cause spontaneous abortion or premature birth.

Herpes is equally common in males and females. It occurs worldwide and is most prevalent among children in lower socioeconomic groups who live in crowded environments. Saliva, stool, urine, skin lesions, and purulent eye exudate are potential sources of infection.

Signs and symptoms

• mouth sores
• genital lesions (female) -- may be preceded by burning or tingling sensation
• fever blisters
• blisters or ulcers -- most frequent on the mouth, lips and gums or genitalia
• genital lesions (male) -- may be preceded by burning or tingling sensation
• fever -- may be present especially during the first episode
• enlargement of lymph nodes in the neck or groin

Diagnosis

The appearance of HSV is often typical and no testing is needed to confirm the diagnosis. If diagnosis is uncertain, a swab from the infected skin for culture or smear may be taken and sent to the laboratory for analysis. Laboratory tests include special microscopic examinations and blood tests for antibodies. Some tests are only valid in the early stages, and more than one of these tests may be required to confirm the presence of herpes. Genital herpes can be mistaken for other diseases, including syphilis. A small number of women with genital herpes do not know they have it because it occurs on the cervix.

Treatment

Symptomatic and supportive therapy is essential. Generalized primary infection usually requires an analgesic-antipyretic to reduce fever and relieve pain. Anesthetic mouthwashes such as viscous lidocaine may reduce the pain of gingivostomatitis, enabling the patient to eat and preventing dehydration. Drying agents such as calamine lotion make labial lesions less painful.

Refer patients with eye infections to an ophthalmologist. Topical corticosteroids are contraindicated in active infection, but idoxuridine, trifluridine, and vidarabine are effective.

A 5% acyclovir ointment may bring relief to patients with genital herpes or to immunosuppressed patients with HVH skin infections. Intravenous acyclovir helps treat more severe.

Prevention

Herpes infections can be prevented by avoiding direct contact with sores or ulcers of someone who has an active herpes infection - either on the mouth or on the genitals.

Teens who are sexually active should properly use a latex condom during sexual activity, but even condoms will not completely eliminate the risk of spreading genital herpes while there are active lesions. The only surefire way to prevent genital herpes is abstinence.

Pregnant women who have had genital herpes or any type of genital sores or blisters in the past should always tell their obstetricians before delivery. In some cases, other delivery options - like a cesarean section - can prevent HSV2 from being passed to the newborn.