If the red bumps are confined to a small area of the skin and are fixed in one place, they may be limited dermatitis, or ringworm, or limited eczema. 1. If the red bumps appear in a large area or are distributed throughout the body, they may be urticaria or generalized eczema. 2. 4. If the red bumps appear in areas with dense distribution of hair follicles and sebaceous glands, they may also be infections, which are also known as bacterial infections, and will appear as inflammatory reactions and red bumps.