Cxcccx q433e

INTRODUCTION

•

Verrucae are common lesions of children and adolescent, although they may encounter at any age.

•

They are caused by human papillomaviruses (HPV)

•

Transmission of disease usually involves direct between individuals or auto-inoculation.

•

Verrucae are generally self-limited, regressing spontaneously within 6 month to 2 years.

•

The classification of verrucae is based largely on appearance and location.

•

The lesions of Verruca vulgaris occur anywhere but most frequently on the hands, particularly on the dorsal surfaces and periungual areas.

•

They appear as grey-white to tan, flat to convex, 0.1 to 1 cm papule, with a rough pebble like surface.

PATHOPHYSIOLOGY

Papillomaviruses are thought to have 2 modes of replication: •

Stable replication of the episomal genome in basal cells.

•

Runaway, or vegetative, replication in differentiated cells to generate progeny virus

more

•

Stable replication of the episomal genome in basal cells.

•

Runaway, or vegetative, replication in more differentiated cells to generate progeny virus

•

HPV infects the basal keratinocyte of the epidermis, presumably through disruptions of the skin or mucosal surface.

•

At this location, the virus remains latent in the cell as a circular episome in low copy numbers.

•

Autoinoculation of virus into opposed lesions is common. Spread of HPV infection is usually through skin-associated virus and not blood-borne infection.

•

Cell-mediated immunity (CMI) probably plays a significant role in wart regression;

•

patients with CMI deficiency are particularly susceptible to HPV infection and are notoriously difficult to treat.