Herpes Simplex Infections

Herpes simplexHerpes Simplex Infections (Fever Blisters, Genital Herpes)

– A recurrent viral infection of the skin and mucous membranes characterized by clusters of small inflamed vesicles filled with clear fluid.

Causes and Incidence

The cause is the herpes simplex virus, type 1 or type 2. HSV-1 usually affects oral, labial, ocular, or skin tissues and is transmitted primarily by oral secretions. HSV-2 (genital herpes) affects genital structures and is transmitted by contact with genital secretions, primarily through sexual intercourse. Genital herpes is the most common sexually transmitted disease in the United States, with the highest incidence seen in men 15 to 30 years old. The incidence is increasing among women and neonates, who are infected during birth to an infected mother. About 85% of the population have antibodies against HSV-1. The other 15% harbor the virus as carriers and have intermittent outbreaks, often triggered by diminished immune protection, stress, menses, sun exposure, and cold.

Disease Process

After initial infection the virus incubates and then forms the characteristic lesions on mucous membranes and skin. After the lesions resolve, the virus resides in the nerve ganglia and remains dormant until triggered anew by some stimulus or stressor that reactivates lesion formation. The disease is communicable when the lesions are present, and some transient shedding of the virus occurs even when no lesions are visible.


The classic symptoms are itching followed by the eruption of small, tense, clustered vesicles around the mouth, conjunctivae, or genitalia. These vesicles persist for a few days, then dry and crust over; they disappear in about 21 days. Atrophy and scarring may occur if lesions recur at the same site.

Potential Complications

An initial infection of HSV-2 during pregnancy can lead to spontaneous abortion, premature labor, uterine growth retardation, and microcephaly. Blindness may result from ocular infections. Urethral strictures may develop in men, and women are at increased risk for cervical cancer. Herpes infections can be very severe in individuals with AIDS, leading to esophagitis, colitis, pneumonia, and neurologic syndromes.

Diagnostic Tests

A clinical examination and history lead to a tentative diagnosis, which is confirmed by culture of lesions and biopsy results.



Analgesics for pain, topical antipruritic lotions; acyclovir to reduce symptoms in HSV-2 infections; topical and systemic antiinfective drugs for secondary infections.

Cleansing of lesions with soap and water; lesions kept dry; mouthwashes for oral lesions; instruction about the spread and recurrent nature of the disease; use of protection during sexual activity; precautions and careful monitoring if an infected woman is considering pregnancy; emotional support to assist in coping with diagnosis.