Pictures of Hives to Help Identify a Rash

How to Recognize the Different Types

Hives, also known as urticaria, are a type of skin rash with raised, red, itchy bumps or welts. Hives are a common condition that affects up to 20% of the population at one time or another.

Hives have a number of different causes, including allergic reactions, bee stings, infections, or even stress. They can affect any person at any age, on any part of the body, with symptoms of a rash, itching, and stinging or burning.

In this gallery are pictures of hives, with a discussion of different types and notable characteristics of each. The article will also explain why different hives develop and what can be done to treat them.

Close-Up of Hives Caused By Infection

Heather L. Brannon, MD

Hives and Their Causes

Hives are often idiopathic, meaning that they can develop spontaneously for no known reason.

If a cause can be found, it is most often the result of a reaction to one of the following:

  • Allergic reactions to food, medications, or insect bites
  • Bacterial or viral infections, including strep throat, colds, and mononucleosis
  • Physical triggers like cold temperatures, pressure, scratching, or vibrations
  • Sweating events like exercise or being in an overheated environment
  • Psychological stress
  • Sun exposure (uncommon)
  • Water exposure (uncommon)

The above photo is an example of hives caused by a ​viral infection. Hives caused by an infection tend to be generalized (widespread) rather than localized (as can occur with things like a bug bite).

Does Covid Cause Hives in Adults?

Yes. COVID-19 is associated with a rash in many people diagnosed with the virus. The hives form in different patterns, including patches, itchy bumps, and blisters that look like chicken pox. Most people who have the rash find it lasts about eight days. COVID-related hives often itch, and some may require medical treatment.

Chronic Hives

Hives
anand purohit / Getty Images

Hives can usually be diagnosed based on their appearance. The hives may be acute, meaning that they develop rapidly and tend to resolve quickly. They may also be chronic, meaning that they persist for more than six weeks and/or recur frequently over months or years.

Chronic hives are most often idiopathic and will develop spontaneously for no apparent reason. It is thought that some sort of autoimmune disorder may be involved.

Chronic hives may also be inducible, meaning that a known trigger causes them. One such example is hives that develop after wearing a tight belt or clothing, referred to as pressure-induced urticaria.

People with chronic hives tend to have co-occurring atopic (allergy-related) conditions like asthma, atopic dermatitis (eczema), and allergic rhinitis (hay fever).

Chronic hives tend to cause splotchy welts, as in this picture, with raised edges and defined borders.

Chronic hives are those that last for more than six weeks and/or recur frequently over the course of months or years. Most cases of chronic hives are idiopathic (of unknown origin).

Acute Hives

Urticaria Rash (Hives) On Legs Due to Exam Stress

DR P. MARAZZI / SCIENCE PHOTO LIBRARY / Getty Images

Acute hives are common and tend to be harmless, Most clear up within a day and don't leave any lasting marks. This is a picture of acute hives.

A doctor may prescribe an oral antihistamine to help relieve the itching or recommend simple home remedies to help relieve the discomfort. Fortunately, most cases resolve on their own.

This doesn't mean that all cases of acute hives are harmless. If hives develop suddenly and are accompanied by shortness of breath, wheezing, and the swelling of the face or tongue, it could be a sign of a potentially life-threatening, whole-body allergy known as anaphylaxis.

Other signs of anaphylaxis include dizziness, irregular heartbeats, and a feeling of impending doom. 911 emergency assistance is needed.

Anaphylaxis and Hives

Call 911 if acute hives are accompanied by shortness of breath, wheezing, dizziness, irregular heartbeat, and swelling of the face or tongue. These are all signs of a medical emergency known as anaphylaxis.

Spongy Hives

Close-Up of Spongy Hives

Heather L. Brannon, MD



Hives are caused when the immune system responds abnormally to certain physical, environmental, and even psychological triggers.

When this happens, the immune system will instruct immune cells in the skin (called mast cells) and immune cells in the blood (called basophils) to break open and release inflammatory chemicals, including histamine, into the body.

Histamine causes tiny blood vessels in the skin to widen in order for larger immune cells to access the site of the supposed injury. The widening causes fluids to leak into surrounding tissues, causing the raised, red welts we recognize as hives.

Depending on the amount of fluid that gets released, hives can look very "spongy" like this. Or, they can appear flat with well-defined, raised borders.

Hives on Black Skin

Hives will typically appear red on skin, but they're harder to see in people with dark skin tones. Many skin conditions, such as eczema, cause a darker brown or ashen gray color instead. It's also more common for people with brown or black skin to develop papules (small bumps) and scaly patches.

Dermatographism

Appearance of the word "Dermatographia" on a human arm 15 minutes after the letters have been traced with a blunt object on the skin. A type of urticaria or "hives", also known as dermatographic urticaria, dermatographism, or "skin writing".
R1carver/Wikimedia Commons/CC-BY-SA-3.0

When people refer to hives, they often think of an allergic response to food or medications. But, hives can also be caused by physical stimuli that cause the skin to form raised, red welts.

One example is dermatographism. Dermatographism is a form of chronic urticaria caused by stroking the skin with pressure. The term "dermatographism" literally means the ability to write on the skin.

Dermatographism is among the most common forms of hives, affecting anywhere from 2% to 5% of the world's population. Even so, the exact cause of this condition is largely unknown.

Similar conditions include cold-induced urticaria, pressure-induced urticaria, exercise-induced urticaria, and stress-induced urticaria.

Hives and Physical Exposures

Physical stimuli can trigger hives in some people. The cause of this is largely unknown. Triggers can include cold, pressure, exercise, stress, or scratching (referred to as dermatographism).

Summary

Hives (urticaria) are a type of rash that causes raised, red, itchy bumps or welts. Hives may be acute, appearing quickly and usually resolving quickly on their own. Or, they may be chronic, lasting for more than six months and/or recurring frequently over months or years.

There are many possible causes of hives, including allergies, infections, stress, cold, vibration, exercise, and even scratching. Chronic hives are often idiopathic, meaning of unknown origin, and may develop spontaneously for no apparent reason.

Hives are ultimately caused by an abnormal immune response in which inflammatory chemicals, including histamine, are released into the bloodstream and tissues. Antihistamines may be used to relieve the swelling, redness, or itchiness of hives. Many cases clear up on their own without treatment.

Frequently Asked Questions

  • Can emotional stress cause hives?

    Yes. Histamine can cause puffy, red, raised welts known as hives. The sympathetic nervous system churns out histamine when we are under stress—the same chemical responsible for an allergic reaction.

  • What is the difference between a rash and hives?

    Rash is an umbrella term for red, itchy, and irritated skin. Hives are a type of rash that causes raised, red, and often itchy bumps. A heat rash, for example, can be mistaken for hives. So can conditions like chickenpox, or vasculitis, which has many causes and often leads to red-purple skin spots.

  • How long do hives last?

    Without treatment, hives can last for a few days. Taking an oral antihistamine, like Benedryl, or applying a topical treatment can help hives to clear up sooner. You can also use a cold compress to calm the itch.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Heather L. Brannon, MD
Heather L. Brannon, MD, is a family practice physician in Mauldin, South Carolina. She has been in practice for over 20 years.