Possible causes of spots on legs, or leg rashes, include an allergic reaction, irritant contact dermatitis, a viral infection, an autoimmune disorder and varicose veins, according to Healthgrades. Peripheral artery disease and improperly treated diabetes may also lead to leg rashes.
Leg rashes are associated with various conditions, and they can appear as spots or dots with a red, purple, silver or white hue, states Healthgrades. They can peel off or become itchy, raised, flat or scaly. Some rashes affect a large, solid region.
Irritant contact dermatitis is a mild condition that occurs when a person is exposed to an irritant, explains Healthgrades. Individuals who are allergic or sensitive to certain substances, such as insect bites, poison ivy or shaving cream, may experience a severe leg rash. Potential causes of a chronic, persistent leg rash include eczema and psoriasis, which causes raised, itchy spots with red edges and silver scales. Severe causes of leg rashes include a bacterial or fungal infection called cellulitis and allergic purpura, a condition characterized by purple spots on the legs.
Leg rashes accompanied by a feeling of tightened, closed airways may indicate a fatal allergic reaction known as anaphylaxis, notes Healthgrades. Contact a medical professional immediately if an allergy-associated rash is accompanied by wheezing, shortness of breath, or a swollen face, mouth or throat.