You may have an allergic reaction to a medicine that causes a skin change, or you may develop a skin reaction when you are out in the sun while you are taking a medicine (this is called photosensitivity). Rashes, hives, and itching may develop, and in some cases may spread to areas of your skin that were not exposed to the sun (photoallergy). For more information, see the topic Allergic Reaction.
Skin changes can also be caused by:
- Autoimmune diseases, such as lupus and scleroderma.
- Reactions to a bite, such as Lyme disease from a tick bite. For more information, see the topic Lyme Disease.
- Bacterial skin infections, such as impetigo and cellulitis.
- Viral infections, such as chickenpox, shingles, or fifth disease.
- Liver problems, such as hepatitis, which may cause your skin and the whites of your eye to turn yellow (jaundice).
Common skin changes
Some common skin growths include:
- Moles. Most people have between 10 and 40 moles. You may continue to form new moles until you are in your 40s. Moles may change over time. They can gradually get bigger, develop a hair, become more raised, get lighter in color, fade away, or fall off.
- Skin tags. These are harmless growths that appear in the skin folds on the neck, under the arms, under the breasts, or in the groin. They begin as small fleshy brown spots and may grow a small stalk. Skin tags never turn into skin cancer.
- Seborrheic keratoses, which are harmless skin growths that are found most often on the chest or back; occasionally on the scalp, face, or neck; and less commonly below the waist. They begin as slightly raised tan spots that develop a crusty appearance like that of a wart. Seborrheic keratoses never turn into skin cancer. For more information, see the topic Seborrheic Keratosis.
Treatment of a skin change depends on what is causing the skin change and what other symptoms you are having. Moles, skin tags, and other growths can be removed if they become irritated, bleed, or cause embarrassment.