Background. Assessment methods for atopic dermatitis (AD) are not standardized, and therapeutic studies are difficult to interpret. Aims. To obtain a consensus on assessment methods in AD and to use a statistical method to develop a composite severity index.Methods. Consensus definitions were given for items used in the scoring system (extent, intensity, subjective) and illustrated for intensity items. Slides were reviewed to address within and between-observer variability by a group of 10 trained clinicians, and data were statistically evaluated with a two way analysis of variance. Two variants of an assessment system were compared in 88 patients at 5 different institutions. Data were analyzed using principal-component analysis. Results. For 5 intensity items studied (erythema, edema/papulation, oozing/crusts, excoriations, lichenification), within- and between-observer variability was good overall, except for edema/papulation which was difficult to assess with slides. In the series of 88 patients, principal-component analysis allowed to extract two unrelated components: the first one accounting for 33% of total variance was interpreted as a ‘severity’ component; the second one, accounting for 18% of variance, was interpreted as a ‘profile’ component distinguishing patients with mostly erythema and subjective symptoms and those with mostly lichenification and dryness and lower subjective symptoms. Of the two evaluation systems used, the one using the rule of nine to assess extent was found more workable than the one using a distribution × intensity product. A scoring index (SCORAD) combining extent, severity and subjective symptoms was mathematically derived from the first system and showed a normal distribution of the population studied. Conclusion. The final choice for the evaluation system was mostly made based on simplicity and easy routine use in outpatient clinics. Based on mathematical appreciation of weights of the items used in the assessment of AD, extent and subjective symptoms account for around 20% each of the total score, intensity items representing 60%. The so-designed composite index SCORAD needs to be further tested in clinical trials.

SynopsisDandruff is a common scalp disorder affecting almost half of the postpubertal population of any ethnicity and both genders. It may, however, represent a stubborn esthetical disturbance often source of pruritus. Skin biocenosis, in particular the Malassezia spp. flora, plays a key aetiologic role, in combination with the unusual capacity of some corneocytes to be coated by these yeasts. Substantial evidence indicates that keratinocytes play an active role in the generation and expression of immunopathological reactions. This is probably the case in dandruff. Upon stimulation of a critical colonization of corneocytes by Malassezia yeasts, the release of pro-inflammatory mediators is increased. This could lead to the subclinical microinflammation present in dandruff. In seborrheic dermatitis, local deposits of immunoglobulins and the release of lymphokines are responsible for the recruitment and local activation of leukocytes leading to the eventual amplification of the inflammatory reaction. Some ancillary non-microbial causes of dandruff may operate through physical or chemical irritants. Many methods have been described for rating dandruff. Our favourite tools are clinical examination and squamometry. Dandruff can precipitate telogen effluvium and exacerbate androgenic alopecia. Antidandruff formulations exhibiting some direct or indirect anti-inflammatory activity can improve both dandruff and its subsequent hair cycle disturbance. Ré suméL'état pelliculaire est une affection commune du cuir chevelu atteignant près de la moitié de la population des individus post-pubères, quels que soient leur ethnie et leur sexe. Cette affection peut s'avé-rer rebelle chez certains. La biocénose cutanée, en particulier la flore des Malazzezia spp., joue un rôle étiologique clé, de même que la capacité particulière exprimée par certains cornéocytes de pouvoir se couvrir de ces levures. De nombreux arguments convergent pour affirmer que les kératinocytes jouent un rôle actif dans la génération et l'expression de réactions immunopathologiques. C'est vraisemblablement le cas dans l'état pelliculaire. Lors de la stimulation par une colonization critique de cornoècytes par les levures Malassezia, la liberation de médiateurs pro-inflammatoires est accrue. Cela conduirait à la micro-inflammation infraclinique des pellicules. Dans la dermite séborrhéique, les dépots locaux d'immunoglobulines et la libération de lymphokines seraient responsables du recrutement et de l'activation locale de leucocytes aboutissant à une amplification éventuelle de la réaction inflammatoire. Certaines causes accessoires nonmicrobiennes des pellicules peuvent intervenir par le biais d'irritants physiques ou chimiques. De nombreuses méthodes d'évaluation des pellicules ont èté décrites. Dans notre laboratoire, l'examen clinique et la squamométrie sont nos outils favoris. Les pellicules peuvent précipiter un effluvium télo-gène et exacerber une alopécie androgénétique. Des formulations antipelliculaires possédant une

Most active antidandruff shampoos exhibit a strong activity against the yeast Malassezia ovalis. The present study was undertaken to compare the prolonged antifungal effect of three proprietary shampoos containing either 2% ketoconazole, 1.5% zinc pyrithione or 2.5% selenium sulphide. Superficial squames were harvested from the scalp in the days following a 6-week antifungal shampoo treatment. Counts of yeasts highlighted by a fluorochrome were made using computerized image analysis. Data show the increased duration of yeast reduction for the ketoconazole shampoo over the two other formulations. The lingering effect of ketoconazole is explained by the combination of its antifungal and pharmacokinetic properties.

Superficial fungal infections affect millions of people throughout the world. Among them, tinea represents cutaneous infections by dermatophytes. Therapeutic strategies depend upon the affected body site. Hence, clinicians distinguish several types of tinea including the corporis, faciei, cruris, pedis, manuum, capitis, barbae and unguium variants. There are several ways of tackling the tinea problem. Numerous topical and oral antifungals are available today. Topical antifungals remain the most commonly recommended treatment for many superficial dermatophytoses. Active compounds include imidazoles, morpholines and allylamines, with a few other miscellaneous drugs. The recent development of new generation oral agents (fluconazole, itraconazole, terbinafine) has enhanced the armamentarium against difficult-to-treat tineas. The antifungal efficacy and pharmacokinetic profiles of these drugs allow shorter durations of treatment and the innovative use of intermittent pulse regimens. The modern formulations fully meet the requirements of being well tolerated, involving little risk and acting specifically against relevant pathogens. However, the response rates to date do not always come up to the high expectations offered by in vitro studies.

In a series of fibrotic and sclerotic diseases including scars keloids fibromas scleroderma and lichen sclerosus et atrophicus, we found modifications in the dendrocyte population. Dendrocytes were numerous in fibrotic diseases associated with little deposits of collagen. Conversely, they were almost absent in sclerotic diseases when the lay-down of collagen was prominent. We hypothesize that dendrocytes, by their content in factor XIIIa, may limit the accumulation of collagen in the skin.