Prickly heat – forms, causes, and treatment

Prickly heat (also heat frieseln or welding frieseln), millet grain-like papules or pustules on the skin. They arise when the welding are constricted glands in the skin, or blocked. The sweat can no longer pass through the various layers of the skin to the outside, to most to Verdun. He collects instead in the skin and irritates it. In consequence of kleinherdige skin changes that can range from superficial blisters to deep reddish nodes.

The rash is not contagious. Some of the heat-induced pimples are visually annoying, and others associated with inflammation and itching. Many people think of heat-pimples, first of all, to newborns, infants and small children. But even in adults, they can manifest themselves, particularly in warm, humid weather conditions. Specialist doctors refer to this as a heat rash. The term goes back to the Latin word “milium” for “grain of millet”.

Table of contents

Different forms of prickly heat

Doctors differentiate between the different types. The Miliaria-forms differ in their clinical appearance as well as their fine-tissue (histological) composition. That is, they can vary in terms of symptoms and signs. You will be classified as a priority then in which layer of the skin, the sweat ducts are narrowed or blocked. In General, Doctors speak of four different basic forms: Miliaria cristallina, Miliaria rubra, Miliaria, pustular, or Miliaria profunda.

Heat pimples are caused when sweat glands are narrowed or blocked. They can vary in shape and appearance depending on the type. (Image: poravute/

Small water-clear vesicles with crystalline frieseln (Miliaria cristallina)

Crystalline friesel (Miliaria cristallina) apply to pimples as the mildest Form of heat. Affected here are the top sections of the sweat glands excretory ducts. These are located in the outermost skin layer or the top layer of the Epidermis (upper skin) – the so-called Stratum corneum. Due to the Blockade in the upper skin, the sweat pours directly under the outermost layer of skin and causes small, but visible sores and spots.

The bubbles can be by touch easy to open. When you Open the bubbles, the water comes out clear liquid. The blisters are filled with a milky liquid, is also spoken by a Miliaria alba. Miliaria cristallina is not accompanied, as a rule, by itching or Stinging. This Form of prickly Heat most often affects newborns and infants. But it may also occur in adults. This is usually done when they are moved from a temperate climate zone and in an area with a tropical climate.

Many small papules on the back in the case of Miliaria rubra

The red Friesel (Miliaria rubra), which is referred to by some as the “red dog”, is the blockage of the sweat ducts in a deeper layer of Epidermis, called the Stratum granulosum. This is still in the outer layers of the skin, but already a little lower than in the case of Miliaria cristallina. The rash affected skin areas do not or only very little sweating. Most of the many small nodules will be formed, and erythematous papules in the area of the back. The affected areas of skin to itch or burn and feel rough.

Impermeable clothing leads to an intensification of itching or burning, particularly at higher ambient temperatures. Red Frieseln an increased risk for heat stroke. In most cases, the characteristic rash seen in adults, after the ambient temperatures are very hot. Miliaria rubra may develop but also immediately after the increase in temperatures. In newborns and infants red Frieseln occur primarily between the first and third week of life.

In Miliaria rubra, there are usually small, reddish pustules on the back, accompanied by itching and Burning. (Image: angkhan/

Pustular rash in Miliaria, pustular

Miliaria, pustular is a special form of Miliaria rubra. Here, the heat-pimples are infected bacterial. They are inflamed and form purulent pustules. Miliaria, pustular can, however, also arise on the soil of other skin diseases, if they are in violation of Welding passes or block.

Solid, skin-colored nodes in Miliaria profunda

In the case of a Miliaria profunda the sweat, are skin gears up in the under the upper skin lying in the leather (Dermis) – the so-called Stratum papillare – blocked or narrowed. The sweat can not flow up into the upper layers of the skin and disappears, therefore, deeper in the skin. Accordingly, the heat pimples from forming in the deep layers of the skin.

The Miliaria-Form is rare and manifests itself on the basis of fixed, and flesh-coloured knots or thickenings. These are similar to the surface of the skin, sometimes a goose bumps. A Miliaria profunda feels mostly not unpleasant, significantly reduce the sweat production. It relates in particular to adults who have already suffered in the run-up repeatedly at a Miliaria rubra. It shows, also, especially after sports and other sweat-inducing activities.


In the layers of the skin are two different types of welding are glands: the eccrine and apocrine sweat glands. Ekkrine sweat glands (Glandulae sudoriferae eccrinae) are everywhere to be found in the body. The Opening of your execution gear is located directly on the surface of the skin. Apocrine sweat glands (Glandulae sudoriferae apocrinae) result in the so-called Infundibulum of the hair follicle (= a funnel-shaped outlet of the hair on the surface of the skin). They come from according to skin in hairy areas of the body such as the head, the armpits or groin area.

Miliaria or prickly Heat affect glands, the eccrine sweat. With increase in ambient temperature, the vegetative stimulate nervous system glands this type of welding. These but weld that passes through the sweat ducts to the surface of the skin. There, the sweat evaporates and cools by the dissipated heat of Evaporation of the organism. With heat rash-associated rashes occur when the eccrine sweat glands and ducts are narrowed on their way to the skin surface, or otherwise blocked. The sweat evaporates on the skin, but remains in the affected skin layers and this leads, finally, to hardware, changes to the skin, inflammation and rashes.

The Problem is amplified, as soon as the outside temperatures rise sharply and the body is warm. Inflammation, redness, and itching caused mostly agents on the ground of an additional colonization of the execution gangs with bacterial. What is the narrowing or blockage of the execution is ultimately based on exact loss is not clear, in any case, clearly.

Prickly heat in the newborn

Newborns often have prickly Heat. This is partly due to the fact that newborns are only after the first week of life capable of sweating. In addition, the welding are glands already been created with the birth, the excretory ducts of sweat are not formed glands still full. In the case of increased sweating in the still very sensitive passes on to tear easily and be clogged by the welding. Therefore, heat pimples can be a indication that the newborn child is dressed warm. This is especially true for newborns who must spend their first days of life in the incubator.

Heat pimples often occur also in newborns, because of the sweat glands, respectively, the outputs of which are not yet fully formed. (Image: triocean/

Heat pimples can indicate a febrile illness. In newborns and infants, prickly Heat can occur more frequently on the head, neck, back, chest and shoulders. Also a Manifestation in the armpits or in the groin is not unusual.

Prickly heat in adults

In adults, the Affected heat pimples from forming, especially in the case of “sweaty” activities such as endurance sports or physically strenuous work. This is especially true if at the same time, wet-warm and tropical-like weather conditions. In addition, foster also in adults, fever, infections, the development of Miliaria. Furthermore, increases to warm clothes or bedding as well as a longer to be observed bed rest the risk of prickly Heat. Generally speaking, can manifest itself heat-pimples anywhere on the body. They show, however, is often in skin folds or areas of the skin, in which the clothes irritated the skin by friction. Therefore, factor for prickly Heat is also Overweight as a potential risk.

Diseases and treatments with an increased risk

In addition, certain diseases and medicines can lead to a development. So, for example, the intake of Isotretinoin (Retinoid or Vitamin A derivative), or Doxorubicin (cytotoxic) can go with Miliaria is associated. Isotretinoin is a medicine used for the treatment of severe acne. It sets the activity of the sebaceous glands and the sebum production is greatly reduced. Doxorubicin belongs to the group of cytostatic agents and is used widely in the treatment of cancer. But it is also a radiological irradiation is associated with Miliaria.

In addition, it is assumed that certain diseases lead to an increased risk. These include genetically-among other things-related disorders such as Morvan’s syndrome (autoimmune disease of the Central nervous system) or pseudo-hypoaldosteronism associated with type I. Also a Stevens-Johnson syndrome can be used with heat rash. As Stevens-Johnson syndrome is a severe skin is referred to a disease, which is caused by an infection or a drug Allergy.

Finally, a number of hormonally-related diseases in increased sweat production and thus to an increased risk. These include the thyroid gland, for example, functions to fail. But also metabolic diseases such as Diabetes mellitus, rheumatic or neurological diseases such as Parkinson’s disease often goes hand in hand with increased perspiration.

Milaria occurs also in connection with diseases such as Parkinson’s disease, or other genetic or metabolic disorders. (Image: Astrid Gast/

The possible methods of treatment

In most cases, the heat pimples are alone, as soon as a sufficient cooling of the skin is taken care of. This applies in particular for light characteristics, such as Miliaria cristallina, which is, as a rule, after a few days. The rash occurs, however, frequently again, as soon as the weather is again warm and humid. In the case of heavier Miliaria-forms can be supportive of a local, external treatment with desiccating powders or shaking mixtures (including dry pins lungs with lotion Zinci, talc, zinc oxide-talc) is useful. These soothe the skin and reduce the itching.

In the Presence of a strong itch, optionally, an orally administrable antihistamine (anti-allergic drug) can relieve the discomfort. In the case of very pronounced symptoms with severe inflammation a ointment with glucocorticoids (among other things, skin can be corticosteroids such as hydrocortisone). These have anti-inflammatory, anti-allergic and antipruritic properties. Bacterial infections can also be with antimicrobial antiseptics such as Clioquinol treated. The infection can not be brought by these substances under control, it can recommend to the doctor, and also an antibiotic.

Home remedies to support the treatment and reduction of perspiration

In addition, cold compresses or cool-moist wash cloth for cooling. As an effective home remedy for the reduction of the sweat production, among other things, sage tea. This leads to a Contract (Together, the sweat glands, which produce, in consequence, less sweat). The sweat production is also promoted by the use of synthetic clothing and shoes with rubber soles. Breathable natural fibers, open-toed shoes such as sandals or leather shoes, however, support the body’s own heat regulation. In addition, some behaviors can help regulate the healing of prickly heat and, in addition, the formation of a heat-related rash prevention:

  • Drop unnecessary clothing,
  • Wearing loose and light clothing made of natural fibers in hot and humid-warm and hot weather,
  • No stays in the shade and avoiding direct sun radiation,
  • Stays in air-conditioned rooms,
  • Use light bedding,
  • Bathing and showering with cool water and subsequent air drying of the skin,
  • Waiver of perfumed skin care products, shower gels and Soaps,
  • Waiver care products based on mineral oil, as this can lead to blockage of the skin pores,
  • Waiver of diaphoretic acting alcohol, coffee and spicy foods
  • and adequate intake of fluids

In order to avoid additional inflammation, heat pimples are not itchy. There is itching and as a result, a “scratch-pulse”, it is recommended to tap with a Finger on the affected skin area. (fp)


  • Zilles, K., Tillmann, B. N.: anatomy, Springer Medizin Verlag, Heidelberg, 2010, p. 593f