This information can guide practitioners and help them inform their patients about what to expect when they receive gefitinib.

Eccrine sweat glands are skin-associated epithelial structures (appendages) that are unique to some primates including humans and are absent in the skin of most laboratory animals including rodents, rabbits, and pigs. On the basis of the known importance of other skin appendages (hair follicles, apocrine glands, and sebaceous glands) for wound repair in model animals, the present study was designed to assess the role of eccrine glands in the repair of wounded human skin. Partial-thickness wounds were generated on healthy human forearms, and epidermal repair was studied in skin biopsy samples obtained at precise times during the first week after wounding. Wound reepithelialization was assessed using immunohistochemistry and computer-assisted 3-dimensional reconstruction of in vivo wounded skin samples. Our data demonstrate a key role for eccrine sweat glands in reconstituting the epidermis after wounding in humans. More specifically, (i) eccrine sweat glands generate keratinocyte outgrowths that ultimately form new epidermis; (ii) eccrine sweat glands are the most abundant appendages in human skin, outnumbering hair follicles by a factor close to 3; and (iii) the rate of expansion of keratinocyte outgrowths from eccrine sweat glands parallels the rate of reepithelialization. This novel appreciation of the unique importance of eccrine sweat glands for epidermal repair may be exploited to improve our approaches to understanding and treating human wounds.

To quantitatively examine the epidermal and dermal cellular and molecular changes that occur after photodynamic therapy of photodamaged human skin.Design: Serial in vivo biochemical and immunohistochemical analyses after photodynamic therapy using topical 5-aminolevulinic acid (5-ALA) and pulsed-dye laser treatment.

Virus-associated trichodysplasia spinulosa (VATS) is a cutaneous eruption of spiny papules predominantly affecting the face that is associated with a distinctive histologic picture of abnormally maturing anagen follicles with excessive inner root sheath differentiation and hyperkeratotic infundibula. Ultrastructurally, intranuclear viral particles consistent with polyoma virus are found. Only 2 patients have thus far been reported. Both had developed the eruption after a kidney transplant. We report 2 additional cases of VATS. One is an 8-year-old boy who presented with facial papules after a kidney transplant. The other is a 19-year-old man with a history of acute lymphocytic leukemia who never had a transplant. He developed a papular facial eruption as well as alopecia. Light microscopic and ultrastructural examinations revealed a spectrum in the severity of the histologic alterations as well as the number of intranuclear viral particles. This report expands the range of pathologic alterations associated with VATS and documents for the first time that it can affect patients without a solid organ transplant. The similarity of the clinical and histologic features of VATS with those previously reported by others as cyclosporine-induced "follicular dystrophy" or "pilomatrix dysplasia" raises the possibility that the described phenomena may reflect the same entity. Increased awareness of the distinct histologic picture associated with VATS will likely lead to more frequent diagnosis of this underrecognized entity.