Functionally active macrophage-derived myeloperoxidase in the skin of drug-induced toxic epidermal necrolysis.

in Dermatology : International Journal for Clinical & Investigative Dermatology (2010), 220(3), 201-7

BACKGROUND: Drug-induced toxic epidermal necrolysis (TEN) probably results from a complex and specific immune cell reaction involving lymphocytes and macrophages. OBJECTIVE: To assess the functional role ... [more ▼]

BACKGROUND: Drug-induced toxic epidermal necrolysis (TEN) probably results from a complex and specific immune cell reaction involving lymphocytes and macrophages. OBJECTIVE: To assess the functional role of macrophages in TEN. METHODS: Immunohistochemistry was performed on biopsies from early blisters developed in 9 TEN patients. The amount of extracellular myeloperoxidase (MPO) was measured by ELISA in TEN blister fluid and serum. Controls were blister fluids taken from 9 second-degree burns. In addition, 3-chlorotyrosine (a specific marker of MPO activity) was searched for using liquid mass chromatography both in TEN and burn blister fluids. RESULTS: Immunohistochemistry revealed numerous CD68+ macrophages in 8/9 TEN patients; 5-20% of these cells and rare CD15+ neutrophils exhibited MPO immunoreactivity, while keratinocytes were negative. The amount of MPO was significantly higher in TEN blister fluid than in TEN serum, suggesting macrophage production of MPO in the skin. In addition, MPO was significantly more abundant in TEN blister fluid than in burn blister fluid. 3-Chlorotyrosine was detected in 7/9 TEN blister fluids, but in only 2/9 burn blister fluids. DISCUSSION: MPO produced by macrophages was functionally active in most TEN patients, leading to the production of hypochlorous acid, a potent oxidative compound that alters keratinocytes. [less ▲]

New insights in toxic epidermal necrolysis (Lyell's syndrome): clinical considerations, pathobiology and targeted treatments revisited.

in Drug Safety : An International Journal of Medical Toxicology & Drug Experience (2010), 33(3), 189-212

Drug-induced toxic epidermal necrolysis (TEN), also known as Lyell's syndrome, is a life-threatening drug reaction characterized by extensive destruction of the epidermis and mucosal epithelia. The eyes ... [more ▼]

Drug-induced toxic epidermal necrolysis (TEN), also known as Lyell's syndrome, is a life-threatening drug reaction characterized by extensive destruction of the epidermis and mucosal epithelia. The eyes are typically involved in TEN. At present, the disease has a high mortality rate. Conceptually, TEN and the Stevens-Johnson syndrome are closely related, although their severity and outcome are different. Distinguishing TEN from severe forms of erythema multiforme relies on consideration of aetiological, clinical and histological characteristics. The current understanding of the pathomechanism of TEN suggests that keratinocytes are key initiator cells. It is probable that the combined deleterious effects on keratinocytes of both the cytokine tumour necrosis factor (TNF)-alpha and oxidative stress induce a combination of apoptotic and necrotic events. As yet, there is no evidence indicating the superiority of monotherapy with corticosteroids, ciclosporin (cyclosporine) or intravenous immunoglobulins over supportive care only for patients with TEN. However, the current theory of TEN pathogenesis supports the administration of a combination of antiapoptotic/antinecrotic drugs (e.g. anti-TNF-alpha antibodies plus N-acetylcysteine) targeting different levels of the keratinocyte failure machinery. [less ▲]

Comment j'explore... une dermatose hypochromique ou achromique.

in Revue Médicale de Liège (2010), 65(2), 109-12

Some skin disorders typically share in common a hypochromic or achromic aspect. The diagnostic approach relies on a directed evaluation of the medical history and a careful clinical examination. In ... [more ▼]

Some skin disorders typically share in common a hypochromic or achromic aspect. The diagnostic approach relies on a directed evaluation of the medical history and a careful clinical examination. In addition, the cyanoacrylate skin surface biopsy helps establish the diagnosis. [less ▲]

Le pilomatricome unique ou multifocal et son pendant malin.

in Dermatologie Actualité (2010), 121

A docetaxel-induced rash on a radiotherapy port.

in American Journal of Clinical Dermatology (2010), 11(5), 367-9

Weathering of the hairless scalp: a study using skin capacitance imaging and ultraviolet light-enhanced visualization.

in Clinical & Experimental Dermatology (2010), 35(1), 83-5

The balding scalp is particularly exposed to sunlight, hence, the overall ageing process modulated by ultraviolet and near-infrared light may be increased at this location. The induced changes are better ... [more ▼]

The balding scalp is particularly exposed to sunlight, hence, the overall ageing process modulated by ultraviolet and near-infrared light may be increased at this location. The induced changes are better revealed under ultraviolet light examination. Any alteration in the epidermal maturation is potentially reflected by stratum corneum changes observed as disturbances on skin-capacitance imaging. [less ▲]

Angiogenic fast-growing melanomas and their micrometastases.

in European Journal of Dermatology (2010), 20(3), 302-7

Malignant melanoma (MM), particularly its fast-growing type, is prone to interstitial, intravascular and extravascular migratory metastases. There is no information linking their growth fraction, the ... [more ▼]

Malignant melanoma (MM), particularly its fast-growing type, is prone to interstitial, intravascular and extravascular migratory metastases. There is no information linking their growth fraction, the configuration of the MM advancing edge, the extent in vascularity and the propensity to metastatic progression. The objective of this study was to determine the growth fraction, the size of vascularity and the contours of the progression border of 32 fast-growing MM with regard to the presence or absence of a micrometastatic spread inside the skin and overt metastases in the sentinel lymph nodes. In vivo high resolution colorimetry was performed as a clinical estimate of MM vascularity. Euclidean geometry and fractal analysis were used on immunohistochemical sections. The relative microvasculature profile area beneath MM, and the fractal dimension D of the MM frontline were assessed. The MIB/Ki-67 index was determined in MM cells. Value a* of colorimetry was similarly increased in the presence or absence of micro-metastases. No difference in growth fraction was revealed between these neoplasms. Correlations were found between vascularity and angiotropism, and between the micrometastatic process and the sentinel lymph node involvement. By contrast, no correlation was shown between vascularity and the fractal D dimension of the MM advancing edge. In sum, this study establishes a link between the extent of MM growth fraction, vascularity and the presence of dermal and nodal micrometastases in fast-growing MM. [less ▲]

Revisiting biothermal effects on erythematous hypertrophic scars during pregnancy.

in Journal of Cosmetic Dermatology (2009), 8(1), 27-31

BACKGROUND: Pregnancy is possibly associated with altered wound healing including the development of hypertrophic or keloidal scarring. The management of these lesions may prove to be difficult, and there ... [more ▼]

BACKGROUND: Pregnancy is possibly associated with altered wound healing including the development of hypertrophic or keloidal scarring. The management of these lesions may prove to be difficult, and there are no universally accepted treatment protocols. Objective To assess erythema fading of hypertrophic scars following cold applications. METHODS: Skin color was assessed using the Visi-Chroma VC100 technology following validation of the method. We compared the effects of freezing or cooling hypertrophic scars developed in 45 Caucasian pregnant women. The effects of liquid nitrogen spray cryotherapy, hydrogel cooling pads, and thermal contact cushions were compared. RESULT: This pilot study showed that the three treatment modalities substantially decreased erythema. The thermal contact cushion appeared to be the most effective biothermal means for achieving this effect. CONCLUSION: Freezing or cooling hypertrophic scars helps reducing erythema of hypertrophic scars. This effect probably results from an inhibitory action exerted on the microvasculature. Data suggest that repeat applications of mild cooling might be more effective than a few short freezing sessions. [less ▲]

Sécrétion sudorale et sébacée

in Expertise médicale continue (2009)

Le diagnostic précoce des cancers de la peau est primordial

Book published by bioderma (2009)