Hives are raised, itchy welts on the skin that can range from the size of a pencil eraser to as large as a dinner plate. They appear suddenly, often in clusters, and typically fade within hours, though new ones can replace them. The welts are smooth and slightly puffy, surrounded by normal-looking skin, and they turn white (blanch) when you press on them.
Size, Shape, and Color
Individual hives are rounded or irregularly shaped welts that sit above the surrounding skin. On lighter skin tones, they appear red or pink. On darker skin, hives look very different: they may match your natural skin color, appear darker than your usual tone, or take on a grayish or purplish hue. Most medical images show hives on light skin, which can make them harder to recognize if you have melanin-rich skin.
Small hives can be isolated spots a few millimeters across. Larger ones spread outward and merge together, forming broad, raised patches that cover significant areas. Even when hives cluster or merge, the welts keep their characteristic raised, smooth texture. They don’t crack, flake, or blister the way other skin conditions do.
The Blanching Test
One of the simplest ways to confirm you’re looking at hives is to press on a welt with your finger. If the redness or color temporarily disappears and the skin turns white underneath, that’s blanching, and it’s a hallmark of hives. The color returns as soon as you release pressure. On darker skin tones, blanching may not be visible, so you’ll need to rely more on the raised texture and itching to identify them.
What Hives Feel Like
The itch is usually the first thing people notice. Hives can itch intensely, and some people also feel a burning or stinging sensation in the welts. The skin around the welts often feels warm. Scratching tends to make things worse. In people with a condition called dermatographism, even light scratching or rubbing produces new raised lines or welts along the path of contact, almost like writing on the skin. These friction-triggered welts usually fade within about 30 minutes.
How Hives Differ From Eczema
Hives and eczema can both cause red, itchy skin, but they look and behave quite differently. Eczema produces dry, flaky patches that may ooze or crust over, and it tends to settle in predictable spots like the hands, face, elbows, and behind the knees. Hives are smooth, raised welts that can pop up anywhere on the body and move around, appearing in one spot, fading, and resurfacing somewhere else within hours. Eczema affects the outermost layer of skin, while hives involve inflammation deeper in the dermis, which is why they’re puffier and more defined.
How Long They Last
A single hive typically appears within minutes and fades within a few hours, though new welts often replace old ones, making it seem like the rash is lasting much longer than it actually is. Acute hives resolve completely within six weeks. If welts keep showing up at least twice a week beyond that six-week mark, it’s classified as chronic hives, which can persist for months or longer.
In most cases, hives disappear without leaving any trace. They don’t scar. However, some people with darker skin develop hyperpigmentation after hives heal, meaning dark spots linger at the sites where welts appeared. These spots can last for weeks or even months before fading on their own.
When Swelling Goes Deeper
Sometimes hives are accompanied by a related reaction called angioedema, which is swelling in the deeper layers of skin rather than on the surface. Angioedema most often affects the face, particularly around the eyes, cheeks, and lips. The swelling feels firm and slightly warm, with mild pain rather than itching. It can appear alongside surface hives or on its own.
Hives with angioedema around the throat, tongue, or lips deserve immediate attention because they can signal a severe allergic reaction. Other warning signs that hives are part of something more serious include trouble breathing, wheezing, a rapid or weak pulse, dizziness, vomiting, or feeling faint. These symptoms together point to anaphylaxis, which requires emergency treatment with epinephrine right away. Even if symptoms improve after an epinephrine injection, a second wave of the reaction can occur, so emergency room follow-up is necessary.
Appearance on Different Skin Tones
Because most clinical references describe hives as “red welts,” people with Black or Brown skin sometimes don’t recognize hives on their own bodies. On darker skin, stress hives may look like raised bumps or welts that are the same color as the surrounding skin, slightly darker, or gray-purple. Dermatographism, the friction-triggered type, shows up as dark brown, purple, or gray lines rather than the pink or red lines seen on lighter skin.
Viral rashes that include hives can also appear gray, purple, or dark brown on Black and Brown skin instead of the classic red. If you’re unsure whether a raised, itchy bump is a hive, the combination of smooth texture, sudden onset, and the way it moves around the body within hours is more reliable than color alone.