How I treat ... basal cell carcinoma by imiquimod.

peer reviewedBasal cell carcinoma is the most frequent cancer in humans. Several clinical types are distinguished. They are bound to distinct evolutive prognosis. The surgical excision is the treatment of choice which is rarely followed by recurrence. However, when the lesion is superficial and non aggressive and when the body site is adequate, topical applications of imiquimod can provoke the neoplastic regression. This type of immunotherapy brings 70 to 90% complete remission. A medical follow-up of the treated site is mandatory for a couple of years

Human Muscle Satellite Cells as Targets of Chikungunya Virus Infection

BACKGROUND: Chikungunya (CHIK) virus is a mosquito-transmitted alphavirus that causes in humans an acute infection characterised by fever, polyarthralgia, head-ache, and myalgia. Since 2005, the emergence of CHIK virus was associated with an unprecedented magnitude outbreak of CHIK disease in the Indian Ocean. Clinically, this outbreak was characterized by invalidating poly-arthralgia, with myalgia being reported in 97.7% of cases. Since the cellular targets of CHIK virus in humans are unknown, we studied the pathogenic events and targets of CHIK infection in skeletal muscle. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistology on muscle biopsies from two CHIK virus-infected patients with myositic syndrome showed that viral antigens were found exclusively inside skeletal muscle progenitor cells (designed as satelllite cells), and not in muscle fibers. To evaluate the ability of CHIK virus to replicate in human satellite cells, we assessed virus infection on primary human muscle cells; viral growth was observed in CHIK virus-infected satellite cells with a cytopathic effect, whereas myotubes were essentially refractory to infection. CONCLUSIONS/SIGNIFICANCE: This report provides new insights into CHIK virus pathogenesis, since it is the first to identify a cellular target of CHIK virus in humans and to report a selective infection of muscle satellite cells by a viral agent in humans

It's a bit chilly, cold is stinging and skin is going to suffer

peer reviewedContrasting with many animals, the human physiological capacity to resist to cold is quite limited. Severe cold exerts its major physiopathological effects on the skin and the whole body. The skin and body thermoregulations become quite rapidly unsatisfactory. Cold is then responsible for a series of dermatoses which could, however, be often prevented by simple means. The severity and the duration of exposure to cold, combined to wind speed, altitude and environmental hygrometry condition the nature and severity of the potential disorders. Some lesions may remain moderate in severity, self-limited and transitory. Others lead to irreversible damage with necrosis of the skin and the deeper tissues. Death secondary to hypothermia is the risk of performing some outdoor activities in inhospitable and extreme cold conditions

How I treat... the critical bacterial colonization of a leg ulcer. The Yin and the Yang features of silver-based dressings.

peer reviewedThe critical bacterial colonizaion of leg ulcers can impair their healing rate, aggravate the patient discomfort and increase the medical and nursing costs. In recent times, the dressings designed for leg ulcers have followed a pace of conceptual revolution. Some of them are now offered containing an antiseptic of the silver salt family. The silver concentraton delivered into the wound bed is important to consider when assessing treatment efficacy. The diversity of the silver-based dressings currently on the European market is as large as their differences in activity. Only a minority of these dressings adequately control the wound biocenosis. Their cost which is high for the patient, must be compared to that of nursing care that may become less important. The expected beneficit is a reduction in healing time

Paroxysmal iatrogenic acne and the epidermal growth factor receptor inhibitors (EGFR)

peer reviewedParoxysmal drug-induced acne is a peculiar condition recognized for decades in dermatology. It can be induced by a variety of drugs. In recent years, the epidermal growth factor receptor inhibitors used in oncology have shown this type of adverse effects. The pathogenic mechanism is likely related to the EGF implication in the rupture of the microcomedo wall resulting in the perifollicular inflammatory reaction typical for acne. Other cutaneous adverse effects have been reported with anti-EGFR drugs including paronychia and xerosis. The dermatological treatments of these drug-induced disorders must be adequately targeted

Actinic keratosis in tune with field photocarcinogenesis. A revisited concept

peer reviewedActinic keratosis should no more be considered as a single neoplasm calling for an individual treatment. The concept of actinic photocarcinogenesis presently turns upside down the perception of skin cancers induced by nonionizing electromagnetic radiations. Currently, the clinician should cope with the whole skin area that has been damaged by chronic exposures to the visible and the invisible spectrum of the light. The therapeutic archetypes are 5-fluorouracile 5% and imiquimod 5% carefully applied to the skin area

The conundrum of inducible nitric oxide synthase in chronic leg ulcers.

Nitric oxide (NO) is a potent biological mediator that can be produced in wounds by activation of inducible nitric oxide synthase (iNOS). Its presence appears to be beneficial to the healing process by promoting vasodilation and boosting both migration and synthetic activity of fibroblasts. Chronic leg ulcers differ from acute experimental wounds because the connective tissue and microvascularization of the ulcer bed are strikingly remodelled in chronic wounds. In addition, a bacterial critical colonization from the environment is also often present and deleterious. As such, NO release in leg ulcers may prove to be beneficial by improving the microvasculature and fibroblast functions, and by its antimicrobial effect. However, any excess in NO could become cytotoxic for keratinocytes, thus impeding re-epithelialization. Furthermore, chronic NO release could be involved in the cancerogenesis process leading to Marjolin ulcer. In conclusion, NO induced by environment factors mediates contrasted effects in wound healing that may be beneficial or detrimental for the patient