The most common side effects occur locally in the areas of skin treated with the steroid. Probably the most well known is thinning of the skin (atrophy), which sometimes results in permanent stretch marks (striae). Fine blood vessels may swell and become prominent under the skin surface (telangiectasia), again a permanent change. There may be a temporary loss of pigment in the areas of skin treated; this may be more noticeable in dark-skinned people. Sometimes the skin may become allergic to the steroid, making the eczema appear to get worse. The skin may also bruise more easily and become more susceptible to infection. For this reason topical steroids should never be used to treat inflamed skin that is also infected, unless the infection is also being treated.