Miliaria / Itching / Heat rash


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By Medicover Hospitals / 11 Feb 2021
Home | symptoms | miliaria
  • The medical name for heat rash is miliaria. It occurs when sweat is trapped because of a blockage in the sweat glands in the deeper layers of the skin. Heat rash is a skin infection that frequently affects children and adults in hot or humid weather. You can develop heat rash when your pores get blocked and sweat can't escape.
  • Article Context:

    1. What is heat rash or heat rash?
    2. Types
    3. Causes
    4. Diagnosis
    5. Treatment
    6. When to visit a Doctor?
    7. Home Remedies
    8. Prevention
    9. FAQ's

    What is heat rash or heat rash?

  • The condition we call prickly heat, also known as a heat rash, occurs in adults and children when sweat gets trapped under the skin. Prickly heat is sometimes called a sweat rash or by its diagnostic name, Miliaria. Children get more than adults because their sweat glands are still growing.
  • It looks like minor bumps surrounded by red skin. It typically occurs in clothed areas of the body, such as the back, belly, collar, upper chest, groin, or armpits. And it improves once your skin cools down.
  • Heat rash occurs most often under hot and humid conditions. It is more common in babies. Active people, newborns in incubators, and people on bed rest with a fever are also more likely to get it.
  • Types of heat rash:

    Crystallina Miliaria:

  • Miliaria Crystalline is the most common and mild type of heat rash. If you have miliaria Crystalline, you will notice small clear or white fluid-filled bumps on the surface of your skin. These lumps are sweat bubbles. The lumps often burst.
  • Contrary to popular belief, this type of heat rash is not itchy and should not be painful. Miliaria Crystalline is more common in young babies than in adults.
  • Miliaria Rubra:

  • Miliaria Rubra, or itch, is more common in adults than in children and babies. Miliaria Rubra is known to cause more discomfort than miliaria Crystalline because it occurs deeper in the outer layer of the skin or epidermis.
  • Miliaria Rubra occurs in hot or humid conditions and can cause:
    • Itchy or itchy sensations
    • Red bumps on the skin
    • Lack of sweating in the affected area
    • Inflammation and pain of the skin because the body cannot release sweat through the surface of the skin
    • Lumps that appear due to miliaria rubra can sometimes progress and fill with pus. Physicians refer to the disorder as miliaria pustulosa when this occurs.

    Miliaria profound:

  • Heat rash is the least common form of heat rash. It can recur frequently and become chronic or long-term. This form of heat rash occurs in the dermis, which is the deepest layer of the skin. Miliaria profoundly occurs in adults after a period of physical activity that produces sweat. If you have deep miliaria, you will notice larger, harder, flesh-colored bumps.
  • Because heat rash keeps the sweat from running off the skin, it can lead to nausea and dizziness.
  • Causes:

  • Heat rash occurs when the ducts of the sweat glands become blocked. This may be due to:
    • sweat glands still developing, such as in newborns
    • a warm and humid environment
    • physical activity
    • fever
    • wear synthetic fabrics close to the skin
    • wear a non-porous bandage
    • prolonged bed rest
    • the use of some medications, especially those that reduce sweating
    • radiation therapy
    • some health conditions, such as toxic epidermal necrolysis

    Risk Factors of Miliaria:

  • Factors that make you more vulnerable to heat rash include:
    • Years: Newborns are the most susceptible.
    • Tropical climates: People who live in the tropics are much more likely to get heat rash than people in temperate climates.
    • Physical activity: Anything that makes you sweat a lot, especially if you're not wearing clothes that allow sweat to evaporate, can trigger a heat rash.


  • Heat rashes are not usually dangerous, but if symptoms last for more than a few days or signs of infection appear, see a healthcare provider. They will examine the rash, possibly using a dermoscopy for a closer inspection. If necessary, they can also take a skin biopsy or use imaging technology to identify the cause of the rash.
  • Changes in the skin are a common symptom of many conditions. Heat rash can look like other health problems, including:
    • Viral infections, such as chickenpox or measles
    • Bacterial infections, such as impetigo
    • Hives, due to an allergic reaction
    • Fungal skin infections, such as yeast infection
    • Insect bites
    • Folliculitis, due to a blockage in the hair follicles
    • Acute HIV
    • A response to HIV treatment
  • If any of the following symptoms arise, they may suggest that the cause of the rash is more serious:
    • Fever
    • Cough
    • Runny nose
    • Fatigue
    • Enlarged lymph nodes
    • Muscle aches


  • Miliaria or prickly heat usually go away on their own, but they can have bothersome symptoms. Many people can benefit from the use of home remedies. Products available over the counter or online, such as calamine lotion or topical steroid creams, can help treat symptoms of redness, irritation, and swelling.
  • The prickly heat treatment also involves cooling down quickly to avoid additional sweat. Sitting in front of a fan or in an air-conditioned room can help. Cold showers or baths can lower body temperature and help prickly heat go away faster.
  • Camphor and menthol can also have a cooling effect on the skin and help reduce itching. In some cases, antihistamine medications can help to reduce itching.
  • People who are prone to stinging heat may find relief by washing their bodies regularly with mild soap after sweating. This will reduce the amount of sweat and the number of bacteria in the skin.
  • When to visit a Doctor?

  • A person should speak to a doctor if they think they are experiencing symptoms of syncope, epileptic fainting, or fainting spells that result from medication. In cases of severe alcohol poisoning, a person may need emergency help. Most people will resume their everyday lives with medication. If a person's fainting spells related to an underlying medical condition, they should stop once the person receives treatment to control the condition.
  • Prevention:

    • Persists or becomes more severe
    • There are signs of infection, such as open blisters or pustular lesions
    • There are signs of heat exhaustion and inability to sweat
    • There are other symptoms, such as fever
  • Many illnesses cause rashes, which can resemble heat rash. The underlying cause may be determined by a doctor.
  • Home Remedies:

    • Use a cold compress: People can apply a cold compress, such as an ice pack or cold washcloth, to the skin area to reduce redness, itching, and inflammation.
    • Take a cold bath or shower: Taking a cold bath or shower cools the skin and can help relieve itching. Using a gentle scrub on your skin can help unblock your pores.
    • Wear loose cotton clothing: Wearing loose-fitting clothing allows air to circulate around the body, keeping it cool.
    • Apply aloe vera: Aloe vera has many medicinal properties and the gel has strong anti-inflammatory effects. People can find that putting aloe vera gel to heat rash will help soothe irritated skin.
    • Apply sandalwood: Try mixing sandalwood powder with water to form a paste and apply it to the area of ​​heat rash. First, people should test the paste on another area of ​​their skin to make sure they don't have an allergic reaction.

    Frequently Asked Questions:

  • They go by themselves. If your heat rash does not go away after 3 or 4 days, or if it seems to be getting worse, call your doctor. In some cases, heat rash can be caused by an infection.
  • Miliaria crystallina is the most common and mild form of heat rash. If you have miliaria crystallina, you will notice small clear or white fluid-filled bumps on the surface of your skin. These lumps are sweat bubbles. The bumps often burst.
  • Use calamine lotion or cold compresses to soothe irritated and itchy skin. Evite the use of creams and ointments containing petroleum or mineral oil, which can further obstruct pores.
  • Citations:

  • JOEM -
  • CABI -
  • PMC -