Extravasation is the diffusion of a product injected intravenously into the perivascular or subcutaneous spaces. Skin necrosis of iatrogenic origin can be observed for example with a subcutaneous perfusion of solution containing potassium chloride or the extravasation of 30% hypertonic glucose serum. Whenever a product is injected, the administration route for which the product has obtained marketing authorisation must be respected and a perfusion time of at least 4 to 5 hours per litre of solution perfused must be observed.