Verruca vulgaris. The common wart is a benign growth caused by localized infection with one of the many types of human papillomavirus. These small DNA viruses are part of the papovavirus group. Warts are especially common among children and adolescents and may occur on any mucocutaneous surface. The hands are a particularly frequent location. The typical wart is a roughsurfaced nodule that may be either lighter or darker than the surrounding skin.
Varicella Chickenpox. Varicella Chickenpox is caused by a virus of the herpes group. The disease is highly contagious and is spread by droplet or direct contact. The incubation period for chickenpox ranges from 11 to 21 days. Prodromal symptoms consist of low-grade fever, headache, anorexia, and malaise. On the following day, the characteristic rash begins to appear. The lesions evolve from erythematous macules to form small papules. Quickly, a clear vesicle arises on this erythematous base. The classic lesion of chickenpox has been poetically described as a “dewdrop on a rose petal.” Over the next several days, the vesicles rupture and then crust. The rash begins on the chest and back and spreads centrifugally to involve the face, scalp, and the extremities. New lesions of chickenpox arise in crops over a period of several days.
Vascular malformations. These are congenital malformations that consist of capillary, venous, arterial, or lymphatic abnormalities. There are often combined alformations that comprise different types of vessels. Examples of vascular malformations include port-wine stains (capillary malformation), cystic hygroma (lymphatic malformation), and venous malformations. Vascular malformations are present at birth and grow proportionately with the child. Some vascular malformations may not manifest themselves until adolescence or adulthood. These figures represent venous malformations on the hand and foot.
Trachyonychia (twenty nail dystrophy of childhood). Any skin disease that affects the nail matrix may result in an abnormal nail plate. There are children, though, who only manifest dystrophy of the nail without any other cutaneous lesions, a condition that has been termed twenty nail dystrophy of childhood. The nails have a rough, sandpaper-like quality as well as longitudinal ridging and occasional splitting at the distal nail edge. Similar nail changes can be seen in lichen planus and alopecia areata. In many patients the condition spontaneously regresses.