Scratching dry skin often breaks capillaries near the surface of the epidermis, causing blood to leak out into the surrounding area temporarily, according to the Mayo Clinic. Certain topical medications for skin conditions also cause the skin to thin, making it more likely to bruise.
Skin dryness is a symptom of multiple skin conditions, such as psoriasis and eczema, according to MedicineNet. Corticosteroids are often prescribed as a topical cream to help reduce symptoms of these conditions, states the Mayo Clinic. While these treatments can help improve the dry skin, they also thin the skin layer and make bruising more likely when the skin gets scratched. Anticoagulants, aspirin and other medications can also contribute to easier bruising.
People with diabetes often suffer from extremely dry skin, and they are also more prone to infection, according to Everyday Health. As a result, diabetics need to see a doctor if they notice any extensive dryness, bruising or discoloration on their skin. Excessive scratching can open small cuts, and make infections more likely.
Bruising is not typically a concern, and it usually heals itself, per the Mayo Clinic. People often bruise more easily as they age, and damaged, dry skin makes this more likely. However, numerous bruises without an apparent source or bruises that do not heal indicate a more serious medical condition that requires a professional examination.