Antiviral agents in dermatology: current status and future prospects

Human herpes simplex virus infections: epidemiology, pathogenesis, symptomatology, diagnosis, and management

Eight of the more than 80 known herpesviruses are human pathogens. Human herpes simplex virus (HSV) is a contagious infection with a large reservoir in the general population. It has a potential for significant complications in the immunocompromised host. In addition, psychological distress caused by the negative stigma associated with genital herpes and visible facial lesions in those experiencing frequent outbreaks renders it a challenging clinical dilemma. This article reviews the epidemiology, pathogenesis, and diagnostic features of HSV infections, providing the clinician with an up-to-date understanding of the available management strategies for mucocutaneous HSV-induced disease.

Keloids demonstrate high-level epidermal expression of vascular endothelial growth factor

BACKGROUND

Keloids are a major cause of morbidity, and arise after operation, injury, or cutaneous infection. Clinically, keloids differ from hypertrophic scars in that they grow beyond the original borders of the injury. Keloids occur most commonly for patients of African and Asian descent, and treatment options are multiple, indicating that there is no entirely satisfactory treatment for keloids. Angiogenesis inhibition has been shown to be effective in treatment of malignancy in both animal models and human beings.

OBJECTIVE

We sought to determine whether keloids produce the potent angiogenic factor vascular endothelial growth factor (VEGF).

METHODS

We performed in situ hybridization for VEGF on keloid tissue and normal skin.

RESULTS

Our study demonstrated abundant production of VEGF in keloids and, surprisingly, the major source of VEGF was the overlying epidermis.

CONCLUSIONS

Our results suggest that the overlying epidermis is the major source of keloid angiogenesis. These findings demonstrate that keloids are angiogenic lesions. Topical antiangiogenic therapy, directed at either down-regulating epidermal VEGF or inhibiting keratinocyte-derived VEGF activity on its endothelial receptors, may be useful in the treatment of keloids.

Viral skin infections in the elderly: diagnosis and management

Over the past several years, there have been advances in the diagnosis and treatment of cutaneous viral diseases in elderly patients. Herpes zoster is caused by reactivation in adults of the varicella-zoster virus (VZV) that causes chickenpox in children. For many years, aciclovir was the gold standard of antiviral therapy for the treatment of herpes zoster. Famciclovir and valaciclovir are newer antivirals, which offer less frequent administration. Postherpetic neuralgia (PHN) refers to pain lasting 2 months or more after an acute attack of herpes zoster. The pain may be constant or intermittent. The treatment of established PHN may include topical anaesthetics, analgesics, tricyclic antidepressants and anticonvulsants, and nonpharmacological therapy may be used to complement such treatment. Therapeutic strategies to prevent PHN include the use of oral corticosteroids, nerve blocks, and treatment with standard antiviral therapy. The three most recently discovered human herpes viruses (HHV-6, HHV-7 and HHV-8), in common with the other members of the family, may cause a primary infection, establish latent infection in a specific set of cells in their host, and then reactivate if conditions of altered immunity develop. These viruses have been associated with an array of disorders, which are important for the clinician to recognise. Cytomegalovirus (CMV) is a member of the herpesvirus family that is very prevalent worldwide. More than 80% of primary infections and 20% of reactivation-producing symptoms occur in transplant populations. Treatment options include intravenous administration of ganciclovir, foscarnet or cidofovir. Herpes simplex virus (HSV) most commonly affects the genital and perioral regions. In the elderly, HSV infection is typically manifest at the vermilion border of the lip. The main concern of recurrent herpes labialis in the elderly is related to potential autoinoculation of the eye or genital area. Treatment with aciclovir, famciclovir or valaciclovir is indicated for these infections. Molluscum contagiosum is caused by a poxvirus, which produces cutaneous lesions that appear as small, firm, umbilicated papules. Immunocompromised patients often do not respond to the usual destructive therapies, and intravenous or topical cidofovir may be useful in these patients.

Antiviral agents

The potential severity of many viral infections and the lack of appropriate treatment for these diseases have been a source of endless frustration and helplessness for clinicians. The newly developed field of antiviral therapy is expanding at an astounding rate, with new discoveries each day. Although physicians are not yet able to cure many of the viral infections, such as HSV, HIV, and CMV, a means of controlling them is available. It is hoped that the research and investigations currently under way will lead to a future era of antiviral drugs that will be able to eradicate these diseases.

Herpes simplex: evolving concepts

A large body of molecular biologic research has begun to clarify some basic aspects of viral latency and reactivation. The clinical definition of herpes simplex virus infection is expanding, with the recognition that the disease is largely asymptomatic and that most transmission occurs during periods of asymptomatic viral shedding. With this awareness, serologic diagnosis has become increasingly important. New treatment modalities are now available, and other promising treatments are in development.