Biomedical subjects
Publications and source records attributed to C Piérard-Franchimont.
Cutaneous infections due to atypical mycobacteria are varied. Their prevalence appears on the rise. The contamination comes from the environment following a breaking, even minimal, of the cutaneous barrier. Mesotherapy, particularly when performed using a mechanical device, is a well recognized iatrogenic origin of this type of microorganism inoculation
Topical calcineurin inhibitors, also called topical immunomodulators or downregulators, represent an innovative class of non-steroidal anti-inflammatory agents. Pimecrolimus 1% cream (Elidel) is one representative drug available for the treatment of atopic dermatitis. Unlike topical steroids, this drug does not affect collagen synthesis and does not alter the dendritic cell functions and the barrier function of the skin.
The artificial light sources are numerous. They emit a more or less delimited spectrum of wavelengths. Ultraviolet light dosimetry allows to control the amount of delivered energy.
Photochemical reactions are numerous in the skin. They generate reactive oxygen species and other biochemical alterations as well. According to their nature, the molecular components of the skin which have been altered by these mechanisms can be repaired with various degrees of efficacy.
The various cell lines of the epidermis and dermis can be activated or conversely altered by actinic irradiations. Keratinocytes, melanocytes, Langerhans cells and connective tissue cells are the main targets.
The integration of the various cell reactions with ultraviolet light is modulated by the phototypes. It is responsible for photo-immunological processes and for photocancerogenesis.
Ethnic (racial) differences exist for a series of physiological skin characteristics. Colour is responsible for typology and resistance to ultraviolet irradiations. Other differences have also been reported for the transepidermal water loss, the size and cohesion of corneocytes, the vascular reactiviy, the biomechanical properties, the pH, the lipidic content, the superficial microflora and the structure of mast cell granules.
The cumulative effect of lifelong sun exposures induces skin alterations which are coined helioderma. The manifestations of helioderma vary according to the body site. This is particularly the case for the prominent differences in the expression of solar elastosis. This condition is commonly more severe on the face and nape of the neck than on the forearms and back of the hands. The age, phototype and behaviour regarding sun exposure are cofactors responsible for the severity of solar elastosis.
There exists a series of photodermatoses due to phototoxic or photoallergic reactions. Anamnestic and clinical clues supplemented by dermatopathological examination and photobiological tests are key features for reaching the correct diagnosis and the adequate choice of therapy.
Most of the cutaneous carcinomas and melanomas are photo-induced cancers. By contrast, some cutaneous lymphomas are inhibited by light exposure. The annual incidence of photo-induced cancers is steadily on the rise.
Physical or chemical photoprotection is mandatory in order to prevent some of the negative effects of ultraviolet light exposure.
Some cutaneous disorders can be treated by light under specific modalities. Balneotherapy, UVA phototherapy, PUVAtherapy, TL 01 phototherapy, extracorporeal photochemotherapy and external photodynamic therapy are representatives of this group of treatment modalities.
Numerous types of lasers can exert different and specific effects in the skin. Devices delivering high intensity of pulsed light can exert similar effect.
Basal 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.
We report the case of a 70-year old man who presented the classical cutaneous signs of chronic arsenicism : palmo-plantar keratoses and lesions of Bowen's disease. Within a few months, the patient developed multiple large superficial basal cell carcinomas on the trunk and several invasive squamous cell carcinomas. A pulmonary cancer with cerebral metastases was also identified. The complications of chronic arsenicism are nowadays rarely encountered. The cutaneous changes should be recongized because they allow to reveal the etiology of some internal lesions. Indeed, the notion of past arsenicism is often missing in the patient records. The recognition of the cutaneous warning signs allows to focus on the overall cancer risk of these patients.
Acne is a disorder affecting the majority of subjects during adolescence that may persist at various grades of severity during adulthood. This disorder may manifest itself at different levels of severity ranging from discrete to severe. The lesions may be sporadic or follow a wild course. The therapeutic strategy depends on these progression characteristics and must fit to each individual patient. This review focuses on the minor but the most frequent types of acne that may benefit from dermocosmetic treatments.
Chemical peels induce the destruction and exfoliation of the epidermis using selected caustic substances. The specific properties of these agents result in a limited and controlled destruction of epidermal layers and of the superficial dermis. The choice of the appropriate method, the preparatory phase and the post-peeling care are very important to reach optimal results. Some types of peeling are routinely used. We briefly report those designed for the superficial and medium depth peelings. The topical application of glycolic acid at high concentration induces a superficial peel resulting in shading of small wrinkles. Trichloracetic acid used at an appropriate concentration acts more deeply and thus represents a good indication for more severe signs of ageing. These peels have been used for decades by dermatologists to improve the visible signs of skin ageing and to treat some alterations of the cutaneous relief.
Sensory irritation is directly bound to the concept of sensitive skin. A large proportion of the population, in particular young women, is affected. The reported symptoms are those of skin discomfort without any visible alteration of the skin. According to the subjects, the timing and the cutaneous sites, various perceptions occur, including pruritus, burning and stinging sensations. Sensory irritation is difficult to quantify because it remains subjective by essence. The condition is sometimes aggravated by some cosmetics, cleaning and cleansing products, wool contact and exposure to cold and dry climate. The responsible ingredients are often agents affecting functions of stratum corneum without being obvious chemical irritants.