Generally topical steroids (application) side effects are present at the site where they are applied such as thinning of the skin, easy bruising, skin infection, etc. Topical steroids are likely to be absorbed through the skin into the body and cause side effects similar to oral steroids, especially if they are used continuously for long period on large areas of the body such as the back. You are right, it affect normal production of steroids in the body which is the function of the adrenal gland. Side effects would include increased risk of getting infection (takes place with very high doses), reduced calcium absorption through the gastrointestinal tract resulting in bone thinning and an increased risk of osteoporosis amongst others. It can suppress growth in children. Some of the more common side effects include changes in appearance, such as acne, development of a round or moon-shaped face and an increased appetite leading to weight gain. Steroids may also cause a redistribution of fat, leading to a swollen face and abdomen, but thin arms and legs. The side effects are usually reversed once the steroids are stopped.