Heat rash: Close look on the different types

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A heat rash is a skin condition affecting children and adults in warm, humid weather. This skin condition develops if the pores are clogged and sweat could not escape.

The root cause of a heat rash is usually friction on the skin surface. Adults end up with heat rash in different parts of the body that rub together such as under the arms or between the inner thighs. Infants often end up with the rash on the necks but also in the skin folds such as the elbows, armpits and thighs.


Miliaria crystallina

Miliaria crystallina is the prevalent and minor type of heat rash. It is characterized as small-sized, white or clear bumps filled with fluid on the skin surface. These bumps often break open. This form of heat rash is common among young infants.

Miliaria rubra

This is also called as prickly heat which is common among adults. The rash can cause more discomfort since it forms deeper in the exterior skin layer.

The root cause of a heat rash is usually friction on the skin surface.

This form is likely to occur during warm or humid conditions and cause the following:

  • Reddened skin bumps
  • Itchiness
  • Diminished sweat in the affected area
  • Sore and inflamed skin since the body could not release sweat via the surface of the skin

Miliaria profundal

Miliaria profundal is an uncommon form of heat rash. This rash can recur often and become chronic. The rash develops in the dermis and typically affects adults after a period of engaging in physical activity that leads to excessive sweating.

If an individual has this type of rash, there are large-sized, rough, flesh-tinted lumps. Since the rash prevents sweat from evaporating away from the skin, it can lead to dizziness and nausea.


The following measures can help prevent a heat rash from forming:

  • Avoid any tight or constricted clothing that does not allow the skin to breathe. Fabrics that wick moisture can prevent the accumulation of sweat on the skin.
  • Do not use any thick creams or lotions that can block the pores.
  • Avoid being overheated particularly during the warm season.
  • Utilize a soap that will not dry out the skin or contain any dyes or fragrances.

It is important to note that heat rash can cause minimal discomfort that settles on its own in a few days.

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