About heat rash

What is heat rash?

Heat rash facts

  • Heat rash occurs when the skin's sweat glands are blocked and the sweat produced cannot get to the surface of the skin to evaporate. This causes inflammation that results in a rash.
  • Common symptoms of heat rash include red bumps on the skin, and a prickly or itchy feeling to the skin (also known as prickly heat).
  • The rash appears as reddened skin with tiny blisters and is due to inflammation. It often occurs in skin creases or areas of tight clothing where air cannot circulate.
  • Heat rash usually fades when the skin is allowed to cool. Medical treatment is necessary only if the area becomes infected.
  • Heat rash can be prevented by avoiding hot, humid conditions, wearing lose fitting clothes and using air conditioning or fans to allow air to circulate.

What is heat rash?

The skin's job is to protect the inside of the body from the outside world. It acts as a preventive barrier against intruders that cause infection, chemicals, or ultraviolet light from invading or damaging the body. It also plays an important role in the body's temperature control. One way that the body cools itself is by sweating, and allowing that sweat or perspiration to evaporate. Sweat is manufactured in sweat glands that line the entire body (except for a few small spots like fingernails, toenails, and the ear canal).

Sweat glands are located in the dermis or deep layer of the skin, and are regulated by the temperature control centers in the brain. Sweat from the gland gets to the surface of the skin by a duct.

A heat rash occurs when sweat ducts become clogged and the sweat can't get to the surface of the skin. Instead, it becomes trapped beneath the skin's surface causing a mild inflammation or rash.

Heat rash is also called prickly heat or miliaria.

What are the symptoms for heat rash?

B symptom was found in the heat rash condition

Adults usually develop heat Rash in skin folds and where clothing causes friction. In infants, the Rash is mainly found on the neck, shoulders and chest. It can also show up in the armpits, elbow creases and groin.

Types of heat rash

The types of miliaria are classified according to how deep the blocked sweat ducts are. Signs and symptoms for each type vary.

  • The mildest form of heat Rash (miliaria crystallina) affects the sweat ducts in the top layer of skin. This form is marked by clear, fluid-filled Blisters and Bumps (papules) that break easily.
  • A type that occurs deeper in the skin (miliaria rubra) is sometimes called prickly heat. Signs and symptoms include red Bumps and Itching or prickling in the affected area.
  • Occasionally, the fluid-containing sacs (vesicles) of miliaria rubra become inflamed and pus-filled (pustular). This form is called miliaria pustulosa.
  • A less common form of heat Rash (miliaria profunda) affects the dermis, a deeper layer of skin. Retained sweat leaks out of the sweat gland into the skin, causing firm, flesh-colored Lesions that resemble goose bumps.

When to see a doctor

Heat Rash usually heals by cooling the skin and avoiding exposure to the heat that caused it. See your doctor if you or your child has symptoms that last longer than a few days, the Rash seems to be getting worse, or you notice signs of infection, such as:

  • Increased pain, swelling, Redness or Warmth around the affected area
  • Pus draining from the lesions
  • Swollen lymph nodes in the armpit, neck or groin
  • A Fever or chills

What are the causes for heat rash?

Heat rash develops when some of your sweat ducts clog. Instead of evaporating, perspiration gets trapped beneath the skin, causing inflammation and rash.

It's not always clear why the sweat ducts become blocked, but certain factors seem to play a role, including:

  • Immature sweat ducts. A newborn's sweat ducts aren't fully developed. They can rupture more easily, trapping perspiration beneath the skin. Heat rash can develop in the first week of life, especially if the infant is being warmed in an incubator, is dressed too warmly or has a fever.
  • Tropical climates. Hot, humid weather can cause heat rash.
  • Physical activity. Intense exercise, hard work or any activity that causes you to sweat heavily can lead to heat rash.
  • Overheating. Overheating in general — dressing too warmly or sleeping under an electric blanket — can lead to heat rash.
  • Prolonged bed rest. Heat rash can also occur in people who are confined to bed for long periods, especially if they have a fever.

What are the treatments for heat rash?

Avoiding overheating may be all you need to do for mild heat rash. Once skin is cool, heat rash tends to clear quickly.

Ointments

More-severe forms of heat rash may require ointments you apply to your skin to relieve discomfort and prevent complications. Such topical treatments may include:

  • Calamine lotion to soothe itching
  • Anhydrous lanolin, which may help prevent duct blockage and stop new lesions from forming
  • Topical steroids in the most serious cases

What are the risk factors for heat rash?

Factors that make you more prone to heat rash include:

  • Age. Newborns are most susceptible.
  • Tropical climates. People living in the tropics are far more likely to have heat rash than are people in temperate climates.
  • Physical activity. Anything that makes you sweat heavily, especially if you're not wearing clothing that allows the sweat to evaporate, can trigger heat rash.

Is there a cure/medications for heat rash?

Several over-the-counter or prescription medications are used to treat heat rash also known as prickly heat, sweat rash, or miliaria rubra.

  • Ointments: Ointments like calamine lotions are recommended to treat the symptoms of heat rash, since calamine lotions have a number of benefits for the skin, partly because it contains zinc oxide. It helps treat heat rash by soothing itchiness. Take some calamine lotion in a cotton pad and dab the lotion onto your rash.
  • Antihistamines: Over-the-counter antihistamines (topical or oral) can relieve the itching associated with heat rash. You need to consult a pediatrician or ask a pharmacist if you are using it for your child.
  • Steroid creams: Hydrocortisone cream, a type of corticosteroid, may be used to help relieve symptoms of heat rash. It can be applied once or twice a day to soothe itching.

While you can use it short-term on your baby’s skin, don’t apply it under the diaper. It could further irritate the skin.

Symptoms
Small, inflamed blister-like bumps and itching or prickling in the affected area,Deep, inflamed lumps,Rash is mainly found on the neck, shoulders, chest, armpits, elbow creases and groin
Conditions
Miliaria crystallina,Miliaria rubra,Miliaria pustulosa
Drugs
Calamine lotions,Over-the-counter antihistamines,Corticosteroids (Hydrocortisone cream)

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