Antiviral drugs in dermatology

This chapter reviews the drugs with antiviral activity used in dermatology, namely those used in the treatment of herpes simplex virus (HSV), varicella-zoster virus (VZV) and cytomegalovirus (CMV) mucocutaneous infections. It also focuses on the cutaneous manifestations of antiviral therapy commonly used in other medical areas, particularly antiviral therapy used in the treatment of human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV).

1 - PATIENT INFORMATION

The most commonly used antiviral drugs in dermatology are aciclovir and valaciclovir.

These drugs are used mainly in the treatment of oral/genital herpes ("cold sores") and zoster ("shingles"), and they can be given orally (both aciclovir and valaciclovir), intravenously (aciclovir) or even topically (aciclovir or cidofovir).

Although they cannot eliminate the virus from the body and therefore cannot cure the infection, they are effective at reducing the pain and overall duration of these diseases, especially if given soon after the appearance of skin lesions (or as soon as the symptoms are noticed in recurrent herpes).

They can also be used to prevent frequent herpes outbreaks. In these cases, they are used daily even when lesions are absent. Such preventive therapy (along with condom use) is also indicated to reduce the risk of transmission.

The use of these prescription drugs is generally safe, but people with renal disease should take lower doses and be closely monitored during therapy.

Patients should always seek qualified medical advice regarding their treatment. Prompt self-treatment of recurrent oral or genital herpetic infections, however, can be beneficial and should begin as soon as symptoms start (itching, burning, stinging or pain).

Antiretroviral medications for the treatment of HIV have diverse and frequent skin manifestations. Lipodystrophy syndrome is a common adverse effect of many of the classes of antiretrovirals and includes a loss of fat in the face, limbs, and buttocks with the accumulation of fat in the upper back and abdomen and, rarely, breast increase. Other cutaneous adverse effects include rashes with multiple patterns, pigmentation abnormalities of the skin and nails and hair disorders. The majority of these manifestations are managed with symptomatic therapy but an expert should always be consulted, since a few are serious and require discontinuation of the drug.

The available therapy for the treatment of HCV chronic infection includes ribavirin, which is known for causing with a relatively low frequency a self-limited pruriginous rash, and a new set of drugs which comprises teleprevir and boceprevir. The latter are responsible for the development of rashes, mostly mild to moderate, without the necessity of suspending the drug.

Antiviral drugs used in the treatment of HBV infection are rarely causative agents of serious cutaneous reactions.