I want some notes about skin problems.
Any change in the skin, including rashes and spots, can be classified as general skin problems. There are rare skin diseases as well as the very common conditions that most people experience during their life. These may include boils and carbuncles, warts, corns and calluses, eczema and dermititis, psoriasis, acne vulgaris, acne rosacea, hives, athletes foot, impetigo, cellulitis, sunburn, basal cell carcinoma, squamous cell carcinoma, and the most serious, malignant melanoma (skin cancer). Teens are very prone to sunburn which can lead to skin cancer,so using appropriate sunscreen with a Sun Protective Factor (SPF) is paramount for healthy skin. Also many teens are prone to acne. There are many over the counter remedies used as treatments, as well as prescriptive medicines that prove to be very effective.
This is such a general question. There are an incredible number of things that can affect the skin. It is the first line of defense for the body against all sorts of things in the environment. The skin can be adversely affected by bacteria, viruses, fungi, parasites, things in the diet, trauma, and radiation. These seem to be listed separately in the eNotes reference section, though you can certainly use the various resources in the biology section. I've included a link from the NIH (National Institute of Health) below, as it appears to have everything you might possibly want all in one place.