Skin rashes, itching, and redness are often caused by common issues like allergies or irritation and usually improve on their own. However, hives can sometimes signal a more serious allergic reaction, especially when accompanied by trouble breathing, swelling of the lips or throat, dizziness, or fainting. These symptoms may indicate anaphylaxis, a medical emergency that requires immediate treatment. Staying alert to rapidly worsening symptoms and seeking prompt medical care can help protect your health.