What would cause sudden red spots to appear on your arms and torso they arent itchy but all seem be appearing in the same places.?

1. Allergic reaction: Allergens like certain foods, medications, insect bites or stings, and even household items can trigger an allergic response characterized by red, itchy bumps or hives.

2. Viral infection: Some viral infections, such as measles, rubella, chickenpox and scarlet fever, can cause red spots or rashes as part of their symptoms.

3. Bacterial infection: Bacterial infections such as scarlet fever or cellulitis can also lead to red spots accompanied by fever and general discomfort.

4. Drug eruption: Certain medications may cause a drug eruption or rash as a side effect.

5. Sunburn: Overexposure to sunlight can cause sunburn, which manifests as red, painful skin.

6. Hives (urticaria): Hives are red, raised, itchy bumps that appear and disappear quickly, and are often caused by allergies, stress, medications or infections.

7. Heat rash: Also known as prickly heat, heat rash occurs when sweat glands become blocked in hot, humid weather, leading to red, itchy bumps on the skin.

8. Folliculitis: This is an inflammation of the hair follicles, typically caused by a bacterial infection and appears as red bumps or pustules around the hair follicles.

9. Insect bites or stings: Bites from insects like mosquitoes, wasps, or spiders can also leave behind red spots on the skin.

10. Skin conditions: Certain skin conditions, such as eczema, psoriasis or atopic dermatitis, can also present with red patches on the skin.

If you're experiencing sudden red spots that don't itch, it is essential to consult a doctor for a proper diagnosis and appropriate treatment. Do not attempt to self-diagnose or self-medicate, as some skin conditions may require specific medical interventions.