[Dermatological manifestations of COVID-19]. / Les manifestations dermatologiques de la COVID-19.

Besides the principal respiratory symptoms, the COVID-19 has been associated with an important array of dermatological manifestations. However, it is not always easy to distinguish whether these skin manifestations are the result of a direct action of the virus on epidermal and/or dermal cell populations, represent a paraviral phenomenon or are a rather fortuitous association. In this review the principal cutaneous manifestations associated with COVID-19 are described as well as their eventual value in terms of diagnostic aid or as prognostic factor. The palmoplantar ischemic pseudo-chilblains lesions are the most frequently observed and are useful for epidemiological purposes. The disseminated vesicular eruptions affect about 23 % of the patient and may witness an initial COVID-19 infection, whereas the vasculitic lesions are rather rare but are currently considered as a factor of bad prognosis.

Outre les symptômes principaux respiratoires, la COVID-19 a été associée avec toute une série de manifestations cutanées. Néanmoins, dans de nombreuses publications, il est assez difficile de discerner si la COVID-19 est directement causale des lésions cutanées, s'il s'agit plutôt d'un phénomène cutané paraviral ou si l'association est fortuite. Dans cette revue, les manifestations cutanées associées à la COVID-19 sont décrites ainsi que leur éventuelle valeur diagnostique et/ou pronostique. Les lésions de type acral (pseudo-engelure) sont les plus fréquentes et surtout utiles pour des données épidémiologiques. Les éruptions vésiculeuses disséminées touchent environ 23 % des patients et peuvent suggérer une infection récente par la COVID-19. Les lésions de type vasculite sont plutôt rares, mais peuvent être considérées comme un facteur de mauvais pronostic.

[Adverse cutaneous reactions to antidepressants]. / Réactions cutanées indésirables aux antidépresseurs.

Due to the widespread usage of antidepressants by the population, they represent a class of drugs which is at high risk for cutaneous side effects. The diversity in the clinical presentations is large. The variability in their severity is large as well. Morbidity may be quite severe, but the vital prognosis is rarely affected.

[How I treat...pityriasis rubra pilaris]. / Comment je traite.... Un pityriasis rubra pilaire.

Pityriasis rubra pilaris is a syndrome of unknown etiology. Six distinct clinical types have been described in infancy and adulthood. Oral retinoids have proven their efficacy. Emollients and topical calcipotriol may improve the clinical presentation.

["Banal dermatomycoses" that cannot be overlooked]. / Des "dermatomycoses banales" qui ne pardonnent pas.

Two young adults presented an interdigital intertrigo and a dyschromic nail alteration, respectively. They were adept of intense sport swimming in pools. Lesions had been misdiagnosed as athlete's foot and onychomycosis, respectively. Several antifungal treatments had been tried without success. After many months of inadequate management, the dermatological examination revealed the presence of two malignant melanomas corresponding to the eroded acrolentiginous and nodular subungueal types, respectively.

The beneficial toxicity paradox of antimicrobials in leg ulcer healing impaired by a polymicrobial flora: a proof-of-concept study.

BACKGROUND: Some of the views contrasting the beneficial and toxic effects of antimicrobials upon wound healing remain controversial. OBJECTIVE: To assess the clinical relevance of histological findings following antimicrobial applications on chronic leg ulcers. METHOD: The present study was performed in three parallel groups of 17 patients suffering from at least 2 similar chronic leg ulcers. Clinical planimetric assessments were performed before and after 3 and 6 weeks of treatment using hydrocolloid dressings. In addition, 1 ulcer in each patient received applications of povidone-iodine (PVP-I), silver sulfadiazine or chlorhexidine digluconate. Histological examinations were made at inclusion and after the 6-week therapy. Time to healing was also recorded. RESULTS: At entry in the study, fibroblasts, macrophages, neutrophils and vessels were abundant in the ulcers. In addition, focal necrotizing vasculitis was related to the microbiological load. Compared to the control lesions, both the healing rate and time to healing of the leg ulcers showed a modest improvement at the sites receiving silver sulfadiazine (2-7%) or chlorhexidine digluconate (-1 to 5%). By contrast, PVP-I increased significantly the healing rate (4-18%, p < 0.01), and time to healing was reduced by 2-9 weeks (p < 0.01). The 3 antimicrobials decreased the bacterial density, and the vascular margination and migration of inflammatory cells, thus abating the vasculitic changes. PVP-I applications did not alter the microvessels and did not significantly reduce the density in dendrocytes and fibroblasts. By contrast, both silver sulfadiazine and chorhexidine digluconate appeared to alter the superficial microsvasculature including the dendrocyte population. CONCLUSION: Although topical antimicrobials may apparently achieve almost similar activity on the bacterial load inside chronic leg ulcers, the toxicity upon host cells was different among these agents. PVP-I appeared to be an efficient compound in these respects exhibiting a positive and relevant clinical effect.

[Pharma clinics. How I treat ... recurrent herpes labialis]. / Pharma clinics. Comment je traite ... un herpès labial récurrent.

Recurrent herpes labialis is a frequent disorder. It occurs following the reactivation of the Herpesvirus (HSV1 and more rarely HSV2) inside the Gasser ganglion. Treatment and prevention of recurrent labial herpes are targeted by specific antiviral agents. Spectacular benefits obtained in the immunocompromised patients are less convincing in otherwise healthy subjects. Other prospective ways of therapy are under consideration, including lipopeptides and physical means aiming at modifying the cutaneous pH.

Stress influence on interface in plasma-sprayed hydroxyapatite coatings on titanium alloy.

During clinical use of hydroxyapatite-coated implants, mechanical stresses are added to pre-existing residual stresses. The magnitude of these stresses affects the coating's performance. In this work we studied, by neutron diffraction and conventional X-ray diffraction methods, the macrostresses induced by a plasma-spraying process in the coating and at the interface. Neutron diffraction is one of the most suitable techniques for studying the strain distribution in a bulk material. X-ray diffraction was used to determine residual stress in the hydroxyapatite coating. Using a neutron diffraction method at the nearest point to the interface, we saw no real difference between the stress observed on coated and that on non-coated samples. With the X-ray diffraction method, it appeared that the stress level was compressive on every sample. The major advantage of the neutron diffraction method is that measurements can be made on a thick coating in a nondestructive way. The disadvantage is the large-gauge volume that we had to use because of the relatively low intensity of the neutron beam. Polishing is necessary for measurements inside the material when using the X-ray method. This destructive method may alter the stress field of the deposit.

Nudging hair shedding by antidandruff shampoos. A comparison of 1% ketoconazole, 1% piroctone olamine and 1% zinc pyrithione formulations.

Hair shedding and hair thinning have been reported to be affected by dandruff and seborrhoeic dermatitis. The present study was conducted in 150 men presenting with telogen effluvium related to androgenic alopecia associated with dandruff. They were randomly allocated to three groups receiving each one of the three shampoos in the market containing either 1% ketoconazole (KTZ), 1% piroctone olamine (PTO) or 1% zinc pyrithione (ZPT). Shampoos had to be used 2-3 times a week for 6 months. Hair shedding during shampoo was evaluated semiquantitatively. Hair density on the vertex was evaluated on photographs using a Dermaphot. Trichograms were used for determining the anagen hair percentage and the mean proximal hair shaft diameter using computerized image analysis. The sebum excretion rate (SER, mug cm(-2) h(-1)) was also measured using a Sebumeter. The three treatments cleared pruritus and dandruff rapidly. At end point, hair density was unchanged, although hair shedding was decreased (KTZ: -17.3%, PTO: -16.5%, ZPT: -10.1%) and the anagen hair percentage was increased (KTZ: 4.9%, PTO: 7.9%, ZPT: 6.8%). The effect on the mean hair shaft diameter was contrasted between the three groups of volunteers (KTZ: 5.4%, PTO: 7.7%, ZPT: -2.2%). In conclusion, telogen effluvium was controlled by KTZ, PTO and ZPT shampoos at 1% concentration. In addition, KTZ and PTO increased the mean hair shaft thickness while discretely decreasing the sebum output at the skin surface.

[The connection between sports and spores. The foot, its mycoses and onychomycoses]. / Il y a sports et spores. Le pied, ses mycoses et onychomycoses.

The epidemiological survey Achillus on over 76,000 subjects has highlighted the high prevalence of foot diseases. In particular, the risk of contracting skin and nail infections of the foot by fungi is quite important during some sport practices. The interhuman transmission is due to propagules commonly called spores. It often occurs by indirect contamination from the soil. Clinical presentations are diverse, largely depending upon the identity of the pathogen fungus. Prevention and treatment of these infections require both patience and perseverance. Boosting the transformation of spores into an active growing phase might paradoxically increase the clinical efficacy of antifungals.

[Contribution of scanning electron microscopy in children with lithiasis]. / Apport de la microscopie électronique à balayage dans la lithiase infantile.

Infrared spectroscopy (IR) was used as the preferential method for determination of the composition of calculi and scanning electron microscopy (SEM) for observation of the IR shape. Our results show the role of SEM for visualisation of the internal ultrastructure and architecture of calculi in children. The authors confirm their previous hypothesis that phosphates favour the nucleation of other compounds, and demonstrate the presence of some trace elements which could play an important role in lithogenesis (eg Si).