Hives can last a variable amount of time. Usually, eruptions may last for a few minutes, sometimes several hours, and even several weeks to months. Most individual hives last no more than 24 hours.
Some food (especially peanuts, eggs, nuts and shellfish) Medications, such as antibiotics (especially penicillin and sulfa), aspirin and ibuprofen. Insect stings or bites. Physical stimuli such as pressure, cold, heat, exercise or sun exposure.
"Stress hives typically look like swollen little mosquito bites," Rachel Nazarian, MD, a New York-based dermatologist said to Health. "They're slightly raised, swollen red or pink patches on the skin, but depending on your skin tone they might look a little different."
First and foremost, don't scratch your itch! Hives can be extremely itchy, and the natural instinct would be to scratch the area that is bothering you. But scratching hives can make them more inflamed and cause them to spread.
Seek emergency medical care. Chronic hives do not put you at sudden risk of a serious allergic reaction (anaphylaxis). If you get hives as part of a severe allergic reaction, seek emergency care. Symptoms of anaphylaxis include dizziness, trouble breathing, and swelling of the tongue, lips, mouth or throat.
Hives and itching often worsen at night because that's when the body's natural anti-itch chemicals are at their lowest.
A sudden onset of hives (acute hives) usually has an identifiable cause or trigger — such as insect stings or bites, medications, certain foods, allergens, or infections. Acute hives go away within a few weeks and are usually effectively treated with antihistamines.
Most cases of hives go away within several days to a couple of weeks. If they last six weeks or longer, you may have autoimmune hives. This happens when your immune system mistakenly targets healthy tissue — in this case, triggering a skin reaction.
Stay away from strong soaps, detergents, and chemicals. These can make itching worse. Put a cool, wet towel on the area to relieve itching. Take a non-drowsy antihistamine, such as loratadine (Claritin), to help stop the hives and calm the itching.
A number of foods have been reported to worsen CU symptoms. These “trigger” foods include alcohol, food additives, seafood, certain vegetables and fruits, fermented foods, and others [6].
About hives
Hives can affect any part of the body, but is common on the torso, throat, arms and legs. The wheals generally appear in clusters, with one cluster getting worse as another gets better. Most wheals disappear without a trace within a few hours, only to be replaced by a new one elsewhere on the skin.
Hives appear as a rapidly spreading, red, raised and itchy rash in splotches or all over the body. Caused by an allergic reaction to medications or food, hives can be a sign of a life-threatening problem when accompanied by difficulty breathing and a drop in blood pressure.
Do not ignore early symptoms. Always take a possible reaction seriously and act quickly. Not every reaction will always look the same; a person can have different symptoms each time. Anaphylaxis can occur without skin symptoms or hives.
Hives usually aren't medical emergencies, though they can feel like a major disruption to your regularly scheduled programming. However, get medical attention post-haste if you have symptoms like fever or swelling of the mouth, tongue or lips, since those are signs of a more serious allergic reaction.
Hot showers or baths can make hives worse. “Heat can cause vasodilation, which essentially gives your hives more blood supply and a chance to spread,” Dr. Ogden says. Instead, take a cold shower or a cool bath to calm the itch.
Drinking plenty of water will help prevent the higher histamine production and alleviate the allergy symptoms.
Anxiety can cause physical reactions in the body, including a rash or hives. If the body is in a constant state of “fight, flight, or freeze” mode, it can cause an increase in certain chemicals, such as histamine. This can lead to the development of a rash or hives.
The immune system takes a big hit when the body is deprived of regenerating sleep, and Breus says this is a common cause of rashes and other skin-related problems.