What Causes Small Red Spots on the Skin?

Small red spots on the skin may be caused by allergic dermatitis, a skin condition typically triggered by exposure to an allergen, leading to skin irritation. Its main manifestations include skin rashes accompanied by itching, stinging, and erythema (redness and swelling). Another possible cause is spider angiomas, which commonly occur on areas such as the joints or lower legs and are usually due to capillary proliferation in the skin.