Cactus spine granuloma.

We describe the case of a 45-year-old woman with a 2-week history of painful erythematous papules on the palmar aspect of the fingertips of her right hand, resulting from contact with a cholla cactus 3 weeks prior in Arizona. The patient initially was given clobetasol propionate ointment, resulting in some improvement; however, the lesions resolved only after punch biopsies were performed to confirm the diagnosis of cactus spine granuloma.

Mohs surgical treatment of a granular cell tumor on the toe of a child.

Granular cell tumors are uncommon, usually benign tumors of neural origin. They are most often diagnosed in the third to sixth decades of life and are infrequently seen in the pediatric population. Although they can be found in a wide distribution throughout the body, more than half occur in the oral cavity and other head and neck sites such as the larynx. We report a granular cell tumor on the distal toe of a 5-year-old child, removed with Mohs surgery. Review of the English language literature revealed four previously reported granular cell tumors treated with Mohs micrographic surgery, none of which was in a child.

The role of calcitonin gene-related peptide in cutaneous immunosuppression induced by repeated subinflammatory ultraviolet irradiation exposure.

Ultraviolet (UV) light is an effective treatment for skin disorders like psoriasis in which the cutaneous neurosensory system may have a pathogenic role. In this study, we examined the possibility that UV modulation of the cutaneous neurosensory system and calcitonin gene-related peptide (CGRP) may contribute to local immunosuppression mediated by repeated subinflammatory UV irradiation. Our results indicated that exposure of hairless mice to subinflammatory UV three times weekly for 4 weeks significantly increased the number of epidermal nerve fibers (ENFs) immunoreactive for CGRP without altering the total number of ENFs. The skin content of CGRP as measured by enzyme-linked immunosorbent assay was also significantly increased after exposure to this dose of UV. These effects were most apparent 1 day after the last UV exposure and declined 1 week after UV. The role of CGRP in UV-induced immunosuppression of contact hypersensitivity was then examined. Our results indicated that UV suppression of epicutaneous 2,4-dinitro-1-fluorobenzene (DNFB) sensitization could be significantly inhibited by a systemically administered CGRP receptor antagonist. A broad-spectrum sunscreen applied before UV exposure inhibited increased cutaneous CGRP and blocked immunosuppression. These findings support a role for CGRP in the local immunosuppression caused by chronic, repeated subinflammatory UV exposure.

Human keratinocytes express functional CD14 and toll-like receptor 4.

CD14 and the toll-like receptor 4 have been known to play an important role in lipopolysaccharide-induced cellular responses in bacterial infections. Although CD14 and toll-like receptor 4 expression has been demonstrated in a number of myeloid cells, much less is known about the expression and function of these lipopolysaccharide receptors on nonleukocytes. In this study, we demonstrate that human keratinocytes are capable of expressing functional CD14 and toll-like receptor 4. Keratinocytes were found to constitutively express CD14 and toll-like receptor 4 mRNA that was augmented by exposure to lipopolysaccharide. Cell surface expression of keratinocyte CD14 and toll-like receptor 4 was detected by flow cytometry. Lipopolysaccharide binding to keratinocyte CD14 and toll-like receptor 4 resulted in a rapid intracellular Ca2+ response, nuclear factor-kappaB nuclear translocation, and the secretion of proinflammatory cytokines and chemokines. These results have important implications for our understanding of cutaneous innate immunity to bacterial infections of the skin.