Noninvasive in vivo confocal laser scanning microscopy is effective in differentiating allergic from nonallergic equivocal patch test reactions.

Patch testing is the gold standard for the validation of contact dermatitis. It relies on the subjective scoring by an evaluator of the inflammatory reaction induced by an allergen applied to the skin. Equivocal reactions imply faint erythema and could represent allergic, irritant, or negative reactions. They constitute approximately 1 % of the positive reactions encountered in patch test practice. Histological evaluation of the equivocal reaction has proven helpful for the correct interpretation but is however time consuming, and its invasive nature is often unacceptable to the patient. In vivo confocal laser scanning microscopy (CLSM) is a novel, noninvasive imaging technique which permits real-time visualization of skin structures and lesions at a resolution close to that obtained by conventional histology. CLSM has been successfully applied for the differentiation between clinically clear-cut allergic and irritant patch test reactions. The objective of this study is to determine the relevance of CLSM in differentiating between allergic, irritant, and negative equivocal patch test reactions. Fifteen patients who underwent patch testing in our clinic were observed as having 20 equivocal reactions. All 20 reactions were evaluated using in vivo CLSM and compared with adjacent normal skin. In vivo CLSM evaluation revealed that 8 of the 20 equivocal reactions (40 %) showed confocal patterns consistent with the patterns encountered in positive allergic reactions. Anamnestic exposure, i.e., detailed assessment of previous related contact with these allergens, confirmed high relevance rates. In vivo CLSM is useful in differentiating between allergic, irritant, and negative equivocal patch test reactions, a differentiation that cannot be made by conventional clinical patch test reading.

Coronary stent restenosis and the association with allergy to metal content of 316L stainless steel.

BACKGROUND: Most intra-coronary stents in use are made of 316 L stainless steel, which contains nickel, chromate and molybdenum. Whether inflammatory and allergic reactions to metals contribute to in-stent restenosis is still a matter of debate. AIM: The aim of this study was to ascertain the relationship between metal allergy and the occurrence of in-stent restenosis. METHODS: Ninety-nine adult patients who underwent two cardiac catheterisations, up to two years apart, were included in the study. Seventy patients had patent stents at the second angiogram (patent stent group) and 29 were found to have in-stent restenosis (restenosis group). All patients underwent patch testing with the relevant metals and the 316L stainless steel plate. RESULTS: Twenty-eight (28.3%) patients were found to have an allergy to at least one metal. There was no significant difference in the prevalence of metal allergy between the patent stent group and the restenosis group (28.6 and 27.6%, respectively; p = 0.921). CONCLUSIONS: Our data do not support the theory that contact allergy plays a role in the pathogenesis of in-stent restenosis.

[The use of tacrolimus in dermatology].

This article aims to review the literature on the use of tacrolimus in dermatology. We tried to focus on the local application of tacrolimus. The local application of tacrolimus is known to be effective for several skin diseases, especially atopic dermatitis. Since the major action site of tacrolimus is activated T-lymphocytes, the drug showed efficiency mostly in inflammatory dermatological diseases including psoriasis, lichen planus, alopecia areata and pyoderma gangrenosum. Tacrolimus lacks most of side effects of local steroids and seems to have better results for short and long term application. We presume that tacrolimus will be widely used on skin diseases, especially when it becomes less expensive.