Red rashes are also common indicators of dermatitis. The rashes are usually painful, and irritating. In most cases, red rashes show up when you have contact dermatitis. Your skin gets these rashes when it comes in contact with an irritant like a chemical or an allergen like poison ivy. Other causes include cosmetics, hair dyes, and leather.The red rashes are not contagious, and they can disappear within three weeks. You can also effectively treat them using home remedies. Some include cortisone creams, cold compress, antihistamines, and moisturizers. If your rash is too painful, then you have to seek medical assistance.Next