The skin is the largest organ of the body, providing a protective barrier against bacteria, chemicals and physical insults while maintaining homeostasis in the internal environment. Such a barrier function the skin ensures protection against excessive water loss. The skin's immune defence consists of several facets, including immediate, non-specific mechanisms (innate immunity) and delayed, stimulus-specific responses (adaptive immunity), which contribute to fending off a wide range of potentially invasive microorganisms. This article is an overview of all known data about 'fragile skin'. Fragile skin is defined as skin with lower resistance to aggressions. Fragile skin can be classified into four categories up to its origin: physiological fragile skin (age, location), pathological fragile skin (acute and chronic), circumstantial fragile skin (due to environmental extrinsic factors or intrinsic factors such as stress) and iatrogenic fragile skin. This article includes the epidemiologic data, pathologic description of fragile skin with pathophysiological bases (mechanical and immunological role of skin barrier) and clinical description of fragile skin in atopic dermatitis, in acne, in rosacea, in psoriasis, in contact dermatitis and other dermatologic pathologies. This article includes also clinical cases and differential diagnosis of fragile skin (reactive skin) in face in adult population. In conclusion, fragile skin is very frequent worldwide and its prevalence varies between 25% and 52% in Caucasian, African and Asian population.
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Epidemiology of fragile skinA recent publication by Haftek describes the results of recent survey realized about 'fragile skin'. Fragile skin was perceived to occur in a substantial proportion of individuals from any given country. The survey was done at 5500 people in a representative sample from the population of five countries: France, Sweden, Spain, Japan and the USA. One of the first results was that all of the respondents were able to answer the question. For them, fragile skin has a very specific meaning. The answers varied depending on the population and their phototypes. Between 25% and 30% of 'Caucasian' respondents (white Europeans), 42% of those with typically 'African' skin and 52% of those with Asian skin reported that their skin was fragile. These people are generally young (around 40% of the European sample were aged 15-34 years) and predominantly female. Fragile skin has an important link to skin pathology, as those who claim their skin is fragile are also more likely to have recently suffered a skin condition, to have acne or to have a history of atopic dermatitis (AD).Those at either end of the age spectrum (babies and elderly patients with dermatoporosis) have generally fragile skin. It can also affect people of all ages in certain areas of the body, such as the eyelids, neck, area around the mouth and areas that receive a lot of sun exposure, such as the d ecollet e or forehead. Dermatologists know th...