Urticaria, more commonly known as hives, appears as raised, red, and itchy welts on the skin. These bumps can show up in clusters or individually, anywhere on the body—including the arms, legs, face, or torso. While hives often fade within hours or days, some people experience recurring outbreaks, which can disrupt daily life and cause significant discomfort.
Hives occur when specialized cells called mast cells release histamine and other chemicals into the bloodstream. This reaction causes fluid to leak from tiny blood vessels under the skin, resulting in swelling, redness, and the characteristic raised patches.
Key Symptoms:
Hives: Red or pale raised bumps that appear suddenly and often vanish within a day.
Itching: Ranging from mild to intense, often exacerbating irritation.
Evanescent Nature: Welts typically fade without scarring, though new ones may form.
Angioedema: Deeper swelling sometimes occurs in areas like the hands, lips, or eyelids, and can be life-threatening if it affects the throat or tongue.
Types of Urticaria:
Acute Urticaria: Lasts less than six weeks, usually triggered by allergies, infections, or medications.
Chronic Urticaria: Persists longer than six weeks, often with no identifiable trigger.
Physical (Inducible) Urticaria: Triggered by external factors such as:
Scratching (dermographism)
Cold exposure
Pressure on the skin
Sunlight (solar urticaria)
Increased body temperature from exercise or stress (cholinergic urticaria)
Common Causes:
Allergic Reactions: Foods, medications, insect bites, or latex.
Infections: Viral or bacterial infections, including colds or strep throat.
Environmental Factors: Temperature extremes, pressure, or sunlight.
Stress: Can worsen existing hives, though not a direct cause.
Autoimmune Reactions: In chronic cases, the immune system may mistakenly attack the body’s tissues.
