What is heat rash and how do we treat it?

Heat rash is common and can be unpleasant, also known as miliaria rubra, prickly heat, summer rash or wildfire rash.

It occurs when a blockage of the sweat glands causes the abruptness is trapped in the skin’s deeper layers. This may result in inflammation, redness and blister-like lesions.

Overweight men, and those who sweat easily, are more likely to get prickly heat. Babies and children are more prone to it because they don’t completely develop their sweat glands.

Fast facts on heat rash

  • Blockage of the sweat glands is the primary cause.
  • Symptoms include red bumps on the surface of the skin.
  • The rash is often described as ‘prickly’.
  • Over-the-counter (OTC) topical antibacterials are a common treatment


Symptoms include small red bumps, known as papules, that can itch or trigger an intense, prickling feeling. They can show up simultaneously in different parts of the body.

Face, back, under the breasts and under the scrotum are the most common areas for heat rash to occur. It can also occur in skin folds and body areas rubbing against clothes, such as the neck, arms, and stomach. They are all places which appear more often to sweat.

A similar disorder is folliculitis, which can occur at the same time. It occurs when hair follicles are filled with foreign matter, such as dead skin cells and sebum, which can then become infected, causing inflammation as well.


heat rash in children
This is what heat rash looks like, small red bumps (papules) on the skin.

Often heat rash is broken down into three types:

Miliaria crystalline – the most common form. Includes tiny, transparent (or white) bumps over the skin surface filled with fluid (sweat). No scratching and no pain. This is more normal in infants compared with adults.

Miliaria rubra – also known as prickly sun, it is associated with red skin bumps, inflammation and a lack of sweat in the region affected. It happens in deeper layers of the skin and hence is painful. When the pumps are growing and being pus-filled it is called miliaria pustulosa.

Miliaria profunda – the least common type of rash fire. It occurs in the dermis-the deepest layer of skin. It can repeat itself and become chronic. Miliaria profunda produces fairly large, tough, bumps colored with flesh.


Heat rash occurs when sweat glands are blocked.
Heat rash occurs when sweat glands are blocked.

Heat rash, or miliaria, occurs when the ducts of the sweat gland are plugged by dead skin cells or bacteria, such as Staphylococcus epidermidis, a common bacterium that occurs on the skin and is often associated with acne.

It can lead to inflammation that appears as a rash if the bacteria get inside the plugged sweat glands.

Anything that causes an individual to sweat more can contribute to miliarium. This is predominant in warm tropical climates.

Due to immobility and illness, long periods of bed rest can make a patient sweat, particularly if they use an electric blanket and other warm bedding.

Wearing too much winter clothing, or sitting too close to a fire or heater can cause a rash.

For example, other drugs make it more possible, psychotropics, which alter mental functions or behavior, and may increase the temperature of the body.

Parkinson’s disease drugs can prevent suddenness, but they too can increase the risk.

Drugs that change the fluid balance in the body, such as tranquilizers, diuretic drugs or water tablets, increase the likelihood to develop symptoms of prickly fire.


Heat rashes are not always harmful, however if symptoms last more than a few days in case the rash is more severe, it is best to seek advice from a doctor.

There are a variety of conditions that can cause rash, since “rash” is a general term for a bump outbreak on the body that changes the skin’s look and feel.

Heat rash can be confused with other conditions, including viral infections such as varicose veins or measles and such impetigo-like bacterial infections.

An allergic reaction to a food or drug can also result in a rash.

It’s important to note other rash-related symptoms such as fever, cough, runny nose, fatigue, enlarged lymph nodes, or muscle aches.

When any of these other signs arise, they may be a sign of a more severe infection requiring urgent medical treatment.


Rashes like prickly heat also recover without having to interfere. Dry, itchy skin may vanish after having been treated with over-the-counter (OTC) preparations for a few days.

  • Topical antibacterials – for example, antibacterial soaps, may shorten the duration of symptoms, even if there are obvious signs of infection.
  • Keep cool – Patients should keep the skin cool, and try to prevent sweating. Staying in an air-conditioned environment, avoiding activities that cause sweating, wearing loose clothing, and taking frequent cool showers can help.
  • Anti-itch preparations – such as calamine or menthol, or camphor-based preparations can help, as can topical steroid creams; it is important to use oil-based preparations with care because they can block the sweat glands further, encouraging the rash to persist.
  • Powder talc admixture – that contains the drying milk protein, labilin, and triclosan, an antibacterial, can be used to prevent infection. The powder stays on the skin and treats bacteria dispersed into bed linens, providing a reasonably dry refuge area for healing.
  • Cooling menthols – may make it easier to get to sleep.

Severe cases can last for several weeks, which can lead to significant impairment. In response to heat this can contribute to an inability to sweat. Secondary infections can occur which can lead to abscesses.

If the rash grows into open blisters or pustular lesions, consult your doctor. It could require more severe, medically supervised care.


Keeping cool and preventing excessive sweating is a good way to prevent heat rash.
Keeping cool and preventing excessive sweating is a good way to prevent heat rash.

Ways to minimize the risk of prickly heat include:

  • avoiding activities that cause sweating
  • using air conditioning to cool the environment
  • wearing light clothing with breathable material, such as cotton
  • avoiding over exposure to hot and humid weather
  • gently exfoliating the skin to remove dead skin cells and sebum that may clog the sweat glands. 

Frequent cold showers or cold baths with mild soap will also help when temperatures rise above normal for an extended period of time to avoid heat rash.

Obianuju Chukwu

She has a degree in pharmacy and has worked in the field as a pharmacist in a hospital. Teaching, blogging, and producing scientific articles are some of her interests. She enjoys writing on various topics relating to health and medicine, including health and beauty-related natural treatments, the nutritional worth of various foods, and mental wellness.