Symptom Definition

A rash is a temporary colouring caused by blood flow that dilates the blood vessels. Rashes manifest themselves in different ways depending on the individual's metabolism. They usually start with the appearance of small red plaques, which later become irritated and the skin gradually reddens. In the case of allergy, the skin is irritated and may show an accumulation of subcutaneous fluid. Irritations occur spontaneously and become more severe when the skin is scratched.