Overview
A rash is a visible change in the skin's color, texture, or surface. It may affect a small area or much of the body and can appear suddenly or develop over time. Some rashes are short-lived, while others come and go or last for weeks.
Key Symptoms
Rashes can cause redness, small spots, raised bumps, scaling, peeling, blisters, or swelling. The skin may itch, burn, sting, feel warm, or become tender. Some people also have symptoms such as fever, sore throat, joint pain, or feeling unwell, which can help point to the cause.
Causes and Risk Factors
A rash can happen after contact with soaps, plants, metals, cosmetics, or other irritants. It can also be linked to allergies, viral or bacterial infections, fungal infections, insect bites, medicines, heat, sweating, or long-term conditions such as eczema or psoriasis. Risk may be higher with sensitive skin, allergies, recent illness, new products, new medicines, or close contact with someone who has an infectious rash.
Who Is Affected
Rashes can affect people of any age and skin tone. Babies and children often get rashes from viral illnesses, heat, eczema, or diaper irritation. Adults may develop rashes related to work exposures, medicines, chronic skin conditions, or immune system problems.
Prevention
Prevention depends on the cause, but helpful steps include using gentle skin products, avoiding known triggers, washing hands, and not sharing personal items such as towels or razors. Keep the skin clean and dry, especially in hot weather or skin folds. If a medicine seemed to trigger a rash, seek medical advice before taking it again.
Diagnosis and Tests
A healthcare professional usually starts by asking when the rash began, where it started, whether it itches or hurts, and whether there were new medicines, foods, travel, illness, or exposures. They examine the skin closely and may ask about fever or other body symptoms. In some cases, tests such as a skin scraping, swab, blood test, allergy evaluation, or skin biopsy may be used to find the cause.
Treatment Categories
Treatment depends on the cause and may include avoiding a trigger, skin care measures, or treatments aimed at inflammation, allergy, fungus, bacteria, or other infections. Cool compresses, gentle fragrance-free moisturizers, and avoiding scratching may help reduce discomfort. Because some rashes need specific treatment and others can worsen with the wrong products, it is important to get medical advice for a severe, persistent, or unclear rash.
When to Seek Medical Care
Seek medical care if a rash is widespread, rapidly spreading, very painful, lasts more than a few days without improvement, or keeps returning. Also get medical advice if there is fever, sore throat, joint pain, mouth sores, pus, crusting, or signs of skin infection. A rash in a baby, after starting a new medicine, or in someone with a weakened immune system should be assessed promptly.
When It May Be an Emergency
Get urgent help right away if a rash happens with trouble breathing, wheezing, fainting, swelling of the face or throat, or severe dizziness. Emergency care is also needed for purple or dark spots that do not fade when pressed, blistering or peeling skin, a rash with high fever or confusion, or a widespread rash after a medicine. These signs can point to a serious allergic reaction, dangerous infection, or severe drug reaction.