Red dots on the skin can arise from a variety of causes, some of which may resolve on their own, while others may need appropriate treatment. Common reasons for these red spots include allergic reactions, residual acne marks, vascular birthmarks, skin spots from angiomas, protein overproduction, heat rash, insect bites, leaking capillaries, and autoimmune conditions.

1. Petechiae and Purpura: These tiny red dots appear due to damaged blood vessels or capillaries. They may be triggered by stress, coughing, or certain medications. While often harmless, they can sometimes suggest underlying platelet disorders.

2. Cherry Angiomas: These small, raised, bright red bumps result from an overgrowth of blood vessels and are generally harmless. They commonly appear with age.

3. Heat Rash: Heat rash occurs when sweat becomes trapped in sweat ducts, leading to itchy, red dots on the skin.

4. Allergic Reactions: Redness can also occur due to allergic reactions to food, substances, medications, or insect stings and bites.

5. Folliculitis: This is the inflammation of hair follicles, typically caused by bacterial or fungal infections, resulting in red, pus-filled dots that can be uncomfortable.

6. Cellulitis: A bacterial skin infection causing redness and swelling, cellulitis usually requires medical treatment with antibiotics.

7. Impetigo: This contagious bacterial infection mainly affects children and is characterized by red sores that open, ooze fluid, and form a crust.

8. Vasculitis: Associated with autoimmune disorders or infections, vasculitis involves inflammation of blood vessels.