Clinical Snippets

Abstract

Hair regrowth after chemotherapy or alopecia areata commonly results in white hair. In mice treated with cyclophosphamide, Sharvov et al (p. 27) showed Fas ligand mediated melanocyte apoptosis. Melanocyte migration accompanied the recovery phase, suggesting new paradigms for treating disorders with hypopigmentation. These studies also suggest a mechanism for the hyperpigmentation of the nail bed seen with antimetabolite therapy. Endemic pemphigus foliaceus in Brazil, Fogo Selvagem, is associated with IgG antibodies against desmoglein-1 in all affected individuals and, surprisingly, half of the normal subjects living in endemic regions (Warren et al, p. 104). The clinically affected individuals and those only with antibodies differed from those with the disease by having an increased anti-desmoglein1 IgG4 level. This two-stage model for disease suggests that preventing the IgG1 to IgG4 conversion might prevent clinical disease. From Star Wars to skin tumor treatment, lasers are usually destructive devices. Yu and co-workers (p. 56) emphasize the “biostimulation” of the low energy Helium–Neon (632.8nm) laser. Basic fibroblast growth factor was induced from fibroblasts and keratinocytes and media from these irradiated cells stimulated melanocyte proliferation and migration. Thirty patients with segmental vitiligo were treated with the laser and 60% of those treated had greater than 50% repigmentation. Further studies of this treatment, especially in those recalcitrant to other forms of treatment, will be of interest. In Doctor's Dilemma, one of Shaw's characters spouts, “Stimulate the phagocytes”; some day we may shout “stimulate the melanocytes”. Prudent sunbathers – possibly an oxymoron – can avoid acute sunburn but have immunosuppression. Kelly and colleagues (p. 65) studied unexposed buttock skin of 119 white-skinned volunteers from 18–35 years for both sun-protective factor responses and the ability to be immunized with dinitrochlorobenzene. Sun Protection Factors (SPF) and Immune Protective Factors (IPF) were calculated. Although the acute sunburn response from simulated sunlight could be suppressed with commercial sunscreen, there was still immunosuppression – possibly due to unfiltered UVA. This study has important implications for the health of the public and those concerned with optimum sunscreen composition and usage and understanding the epidemiology of skin malignancies. Beta-endorphin, a peptide, is the endogenous ligand for the alpha-opiate receptor that stimulates the production of cytokeratin 16, a cytokeratin associated with wound healing and epidermal proliferation in organ culture (Bigliardi et al, p. 145). Beta-endorphins induced fibroblast and capillary proliferation in animal models. These peptides, opiates themselves and modulators of the receptors, may lead to new treatments for chronic wounds. Opiate antagonists might have roles in treating keloids or preventing hypertrophic scars. Watch Fido jump.