Antiviral treatment has been the treatment of choice for all disease manifestations of herpes simplex virus. The antiviral acyclovir is the favored drug for all herpes simplex virus infections. However, several topical antivirals are also available for topical use in HSV eye infections. These antivirals include idoxuridine, triflourothymidine, and topical vidarabine. Oral acyclovir shortens the duration of symptoms in first and recurrent episodes of genital HSV-1 and HSV-2 infections. However, given the expense of oral acyclovir regimens (roughly $1/day) and the modest benefits to the immunocompetant host, routine use of oral acyclovir is not recommended.
Intravenous acyclovir given at 10 mg/kg infusion over 1 h at 8-hourly interval reduces the mortality of HSV encephalitis. Intravenous and oral acyclovir has also been successful at preventing reactivation of HSV in seropositive immunosuppressed patients following chemotherapy or bone transplantation. Unfortunately, acyclovir-resistant strains of herpes virus are becoming more prevalent, especially in HIV-infected individuals. In some patients with an acyclovir-resistant herpes strain, higher doses of acyclovir will clear the lesions. In others, this tactic proves ineffective. For patients in this condition, treatment with Foscarnet may prove ameliorative. However, this drug is usually reserved for patients with severe and widely spread mucocutaneous infections.
Applying ice to an HSV-1 lip lesion during the prodromal period (when irritation is felt but no blistering is apparent) and during the formation of lesions is a folk remedy that I favor. This therapy appears to reduce the number of blisters formed and thus to shorten the healing period. Folk wisdom suggests that this may work by freezing the virus in the lesion, thus destroying the virus. This makes it more difficult for the virus to replicate and create lesions.
In the normal host, treatment and management of chickenpox is aimed at preventing complications. To prevent secondary bacterial infections, daily bathing and good hygiene is of great value. Wet compresses work better to relieve itching than drying lotions. Domeboro soaks are both soothing and cleansing for the treatment of herpes zoster. Aspirin should not be given to children to reduce the possibility of the child developing Reye's syndrom. Acyclovir therapy (800 mg PO five times daily for 5 to 7 days) is useful for the management of chickenpox in adolescents or in adults when the chickenpox is of short duration (lasting a day or less). In children younger than age twelve, acyclovir therapy can be beneficial if initiated during the first 24 hours of the illness at a dose of 20 mg/kg every 6 hours.
In immunocompromised patients, VZV infections are best treated with intravenous acyclovir. This treatment will reduce visceral complications but does not affect the pain or the healing of VZV induced skin lesions. The recommended dosage is 500 mg/square meter every 8 hours for 7 days. Vidarabine may also be used but acyclovir is preferred because it has lower toxicity. Oral acyclovir is not recommended for treating VZV infection in immunocompromised patients. In patients recieving immunosuppressive treatments, it is advisable to wean the immunosuppressive treatments while at the same time undergoing intravenous acyclovir treatment.
In the immunocompetant host, prophylaxis of Varicella-Zoster Virus Infection (Chickenpox) is of little value because the infection is so quick and benign. However, in the immunocompromised host, prophylaxis is recommended to prevent the development of progressive varicella. Zoster immune globulin (ZIG), varicella-zoster immune globulin (VZIG), or intravenous formulation of zoster immune plasma (ZIP) can be administered as prophylaxis. Both ZIG and VZIG should be given within 96 hours of exposure. ZIP can be given later.
Because infectious mononucleosis is typically self-limiting, treatment usually entails only supportive management. Acetominophen may ameliorate fever and pharyngitis. Also, patients should avoid contact sports for 6-8 weeks after the onset of the illness in order to avoid the complication of spleenic rupture. Acyclovir treatment stops oropharyngeal shedding of EBV but the clinical benefits are inapparent.
Because cytomegalovirus (CMV) almost never causes symptomatic disease in the immunocompetant host, it is only in the immunosupressed host that management and therapy of CMV is applicable. Prophylactic measures should be taken to prevent CMV infection of immunosuppressed patients receiving donated blood or organs. Using seronegative blood or organs in seronegative recipients reduces primary CMV infections after transplantation. Freezing, thawing and deglycerlozing the blood from seronegative donors also decreases transfusion-associated CMV transmission. Acyclovir therapy has proven an effective prophylaxis in reducing CMV infection in renal transplant recipients. However, acyclovir does not effectively treat active CMV disease.
In AIDS patients, ganciclovir has proven more effective in treating CMV retinitis or colitis than acyclovir. Foscarnet may be used to treat CMV induced retinitis if the CMV strain being treated in ganciclovir resistant. Although Foscarnet results in longer survival than ganciclovir, it is also linked to higher toxicity. Prolonged prophylactic ganciclovir maintenance regimens are recommended to prevent CMV disease in AIDS patients. Unfortunately, ganciclovir-resistance is often seen in patients who use ganciclovir for more than three months.