Generality
Sudamina, or miliaria, is a skin inflammation caused by the obstruction of the excretory ducts of the sweat glands.
The most characteristic sign of sudamina is the rash, also called a rash or skin rash.
The diagnosis is very simple and is based on a quick objective examination and research into the triggering causes.
Except in particularly serious cases, where drugs can be used for local use, the rash is resolved in a few days and without specific treatments. The only thing that is always recommended to do is to try not to sweat.
What is sudamina?
Sudamina, also known as miliaria, is an inflammatory skin disorder responsible for a rash characterized, depending on the case, by small red spots, white blisters, itching or pustules.
The manifestations of sudamina can affect the whole body; however there are more affected anatomical areas than others, such as the neck, shoulders, armpits, thorax, back and inner thigh (groin).
Figure: a sweat gland.
The sweat glands are independent structures, composed of one of their secreting units (located in a very deep layer of the skin, ie the hypodermis) and their excretory duct (through which sweat is expelled). Furthermore, they are richly vascularized and innervated.
Their function is fundamental for the human body, because they allow to regulate the body temperature, thanks to the emission of sweat. A human being has about 3 million sweat glands, scattered everywhere. The activity of these glands is remarkable: consider that, when the temperature rises considerably, they can also expel 4-6 liters of sweat in an hour.
Epidemiology
Sudamina can affect anyone, but it is more common among people who live in hot-humid climates (for example, tropical areas) and among young children . The cause of this will be explained in the next chapter, when the causes of the miliaria will be discussed.
Causes
Sudamina occurs when the excretory ducts of the sweat glands become clogged, to the point of preventing sweat from reaching the skin surface and evaporating. In other words, what causes the sudamina is an obstruction of the canaliculi that should lead to the surface of the skin the sweat produced by the appointed glands.
But what are the circumstances that lead to the obstruction of the excretory ducts of the sweat glands?
CIRCUMSTANCES THAT BLAST THE SWEETING GLANDS
The obstruction of the sweat glands may be due to:
- An immaturity of the sweat glands themselves . This situation only affects infants and children, as they are the ones with little developed, fragile and easily broken glands; rupture which is usually caused by a considerable production of sweat due to a warm environment and clothing.
- Excessive sweating due to environmental climatic conditions . Hot and humid climates favor sweating. Excessive sweating leads to blockage of the excretory ducts and the appearance of the typical rash of sudamina.
- A very intense physical activity . The sport practiced at high levels, particularly heavy work and, in general, any very intense physical activity, make you sweat a lot. Excessive sweating, as has been mentioned several times, is a possible cause of sudamina.
- A too tight-fitting clothing . Close-fitting clothing prevents adequate sweat elimination, which, by stagnating in the excretory ducts, can block the flow path. It is no coincidence that those who habitually wear close-fitting clothes are more subject to miliaria.
- Certain drugs . Some medicines, such as clonidine, beta-blockers and opiates, increase the activity of sweat glands and the production of sweat.
- Occlusive ointments and skin creams . The application of certain skin products can block the excretory ducts and prevent sweat from escaping. Sudamina, in these cases, occurs even when sweating is normal.
- Exaggerated clothing . Dressing too much or covering yourself too much at night can make you sweat a lot and cause, consequently, a block in the excretory ducts.
RISK FACTORS
The individuals most easily subject to sudamina are those who: live in areas with a hot-humid climate, such as the tropics; they practice activities (no matter whether sporting or working) that make you sweat a lot; they are overweight or are obese; have the habit of wearing more clothes than necessary; they are confined to a hospital bed because of a disease characterized by high fever. To these risk categories we add newborns and children, because they have still immature sweat glands, more subject to obstruction.
Symptoms and Complications
To learn more: Symptoms Miliaria
The most characteristic sign of sudamina is a rash (also called a rash or exanthema ) characterized by the appearance of:
- papules ( small red spots)
- blisters
- sometimes, itching .
Figure: the skin and its layers. The epidermis is the outermost layer, the dermis is the middle layer and, finally, the hypodermis is the innermost layer. The secreting unit of the sweat gland resides in the hypodermis, but the excretory duct, before opening on the surface, passes through the dermis and epidermis.
Figure: crystalline sudamina.
Figure: sudamina in a child.
Figure: the epidermis and its layers. The epidermis, located in the most superficial part of the skin, presents various layers of cells: in the deepest regions there are the cells of the basal layer and the stratum corneum; in the outermost regions, there are the cells of the stratum corneum, shiny and grainy.
The anatomical regions most affected by the skin exanthema are the areas covered by clothing; the clothes, in fact, favor sweating and reduce the evaporation of the sweat produced by the glands.
Depending on the layer of skin where the excretory duct of the sweat gland is obstructed, sudamina can be distinguished as: crystalline sudamine (or miliaria crystalline), sudamina rubra (or miliaria rubra) and deep sudamina (or miliaria deep). Each type of sudamine is distinguished by characteristic symptoms.
CRYSTAL SUDAMIN
Crystalline sudamine, or miliaria crystalline, is the most moderate and least severe form of sudamina: in most cases, in fact, it tends to resolve spontaneously within a few days.
It occurs when the tract of excretory duct passing through the outer layers of the epidermis is blocked. The resulting rash does not produce any type of itching and is characterized by papules and fragile white blisters, filled with liquid.
Crystalline sudamine is the most common form among newborns, however it can also affect adults.
SUDAMINA RUBRA
Sudamina rubra, or miliaria rubra, occurs when the excretory ducts block at the level of the deepest layers of the epidermis. The skin rash that it causes can be characterized by:
- Small red papules
- Itching and stinging pain, similar to the prick of a spine, at the level of the regions concerned
- Reduced or completely absent sweating ( anhidrosis ) in the regions concerned
Sudamina rubra affects more adults than children and represents the typical form of tropical climates and of those who are confined to bed due to a serious illness.
On some rare occasions, it can give rise to pustules ; in this case, one also speaks of pustular sudamine, or miliaria pustolosa .
DEEP SUDAMINA
Deep sudamina, or deep miliaria, is the most severe form of sudamina, but, at the same time, it is also the least common. Typical of adults, it usually arises after repeated episodes of sudamina rubra or as a complication of the latter.
The obstruction of the excretory duct occurs in the dermis, or in one of the deepest layers of the skin.
The skin rash can result in non-itchy, flesh-colored papules, or a reaction very similar to goose bumps .
The anatomical regions involved do not emit sweat (anhidrosis), so that the patient can be the victim of heat stroke, with dizziness, nausea and rapid heartbeat.
WHEN TO REFER TO THE DOCTOR?
Most cases of sudamine resolve spontaneously, within a few days and without special treatment.
If, however, the symptoms do not improve or if the affected areas become unexpectedly swollen, painful and purulent, it is advisable to contact your doctor and request an appointment, because it could be an infection.
Signs of an ongoing infection, which must draw the patient's attention:
- Worsening of pain, swelling and redness in the area affected by the rash
- Sense of heat at the exanthematic area (ie the area with the exanthema)
- Pus release from papules or bladders
- Enlarged lymph nodes of armpits, neck or groin (when, of course, the rash has appeared in these anatomical regions)
- Fever or chills
COMPLICATIONS
In addition to infections of bacterial origin, sudamine can also lead to another dangerous complication: heat stroke .
This, as has been anticipated, is typical of cases of deep miliaria (therefore it is rare), that is of the situations in which there is a deep obstruction, at the level of the dermis, of the excretory ducts.
The symptoms of heat stroke are: drop in blood pressure ( hypotension ), dizziness, nausea, headache and, finally, rapid heart beat .
The people most subject to heat-induced sudamina are individuals who live in very hot geographical areas.
SUDAMINA IN CHILDREN
In infants and children, the characteristic skin rash is more frequent on the neck, shoulders and chest, while it is less common on the axillae, elbows and inguinal regions.
Diagnosis
No special test is required to diagnose sudamine; in fact, an objective examination is sufficient, during which the doctor observes the skin rash and tries to discover the causes.
TRACE THE CAUSES
To understand what caused sudamina, the doctor asks the patient (or family members, if the patient was a newborn or a small child) the type of work performed, the sporting activity practiced, the type of clothing usually worn, the drugs taken, the environment in which he usually lives, if there was a particular event that triggered the symptoms, etc.
Treatment
Sudamina, especially when in mild form, tends to resolve spontaneously within a few days.
To speed up healing, it is very useful to limit all situations that favor the production of sweat or prevent their elimination from the excretory ducts. The use of drugs with local administration is foreseen only in case of severe sudamine and after an appropriate medical consultation.
DON'T SOAP!
When suffering from sudamine, to heal faster, it is sufficient to avoid sweating too much for a few days. To succeed in this, it is good practice:
- Avoid dressing too much, unless the temperature of the external environment makes it essential.
- Avoid dressing incorrectly when exercising.
- Improve the work or home environment by ventilating the area where most of the time is spent. This solution is particularly indicated for patients who suffer periodically from sudamina.
- Don't cover yourself too much at night.
Once these precautions are taken, the skin usually returns to normal quickly.
DRUGS LOCAL ADMINISTRATION
The most serious rashes and the risk of complications are treated with drugs given locally (NB: by local administration it is meant that the medicine is applied directly in the exanthematous area).
The most used medicines and preparations are calamine-based lotions, to soothe the sense of itching, anhydrous lanolin, to prevent the blockage of the excretory ducts and improve the scattered skin eruptions on the body, and corticosteroids, for papules and more severe pustules.
Beware of corticosteroids
Corticosteroids are powerful anti-inflammatory drugs, which should only be taken on medical advice and for limited periods of time. They can cause serious side effects, such as high blood pressure, increased body weight, osteoporosis, glaucoma, diabetes and muscle weakness .
OTHER USEFUL TIPS
Clothes that are too tight-fitting and some skin-spreading preparations slow healing from sudamina, if they do not even cause them to deteriorate.
Therefore, it is good practice to wear loose-fitting clothes, which can make the skin breathe, and avoid the use of non-essential creams or skin lotions.
Prevention
To protect yourself from the onset of sudamina, the following precautions may suffice:
- In summer, wear light, loose and cotton clothes; in winter, cover in a manner appropriate to the temperature. Babies and children should be adequately covered, without exaggerating.
- Avoid all tight-fitting clothes made of skin-irritating material.
- If the season is hot, equip the room where you spend most of the day with an air conditioner or ventilation system.
- Do not cover yourself excessively during the night.
- Do not smear creams and ointments on the skin, unless absolutely necessary. Avoid occlusive products.
As it was easy to understand, the precautionary measures recall the remedies, mentioned in the previous chapter, to heal faster from sudamina.
