Generality
Sudamine, or miliaria, is a "skin inflammation caused by" obstruction of the excretory ducts of the sweat glands.
The most characteristic sign of sudamine is a rash, also called a rash or rash.
Diagnosis is very simple and is based on a quick physical examination and finding the underlying causes.
Except in particularly serious cases, in which local drugs may be needed, the rash resolves 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 sudamine?
Sudamine, also known as miliaria, is an inflammatory skin disorder responsible for a "rash characterized, as appropriate, by small red spots, white blisters, itching or pustules.
Manifestations of sudamine can affect the whole body; however there are some anatomical areas more affected than others, such as the neck, shoulders, armpits, chest, back and inner thigh (groin).
Figure: a sweat gland.
The sweat glands are independent structures, composed of their secreting unit (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: just think which, when the temperature rises significantly, can also expel 4-6 liters of sweat in one "hour.
EPIDEMIOLOGY
Sudamine can affect anyone, however it is more common among people living 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 are dealt with.
Causes
Sudamine arises when the excretory ducts of the sweat glands become blocked, to the point of preventing sweat from reaching the skin surface and evaporating. In other words, the sweat is caused by an obstruction of the canaliculi which should lead the sweat produced by the glands to the surface of the skin.
But what are the circumstances that lead to the obstruction of the excretory ducts of the sweat glands?
CIRCUMSTANCES THAT BLOCK THE GLANDS SWEAT
Sweat gland obstruction may be due to:
- An "immaturity of the sweat glands themselves. This situation concerns only infants and children, as they are the ones who have glands that are underdeveloped, fragile and easy to break; breakage which is usually caused by a considerable production of sweat due to a warm environment and clothing.
- Excessive sweating linked to the climatic conditions of the environment. Hot and humid climates favor sweating. Excessive sweating leads to blockage of the excretory ducts and to the appearance of the rash typical of sudamine.
- A "very intense physical activity. Sport practiced at high levels, particularly heavy work and, in general, any very intense physical activity, cause you to sweat a lot. Excessive sweating, as has been repeatedly mentioned, is a possible cause of prickly heat.
- Clothing that is too tight. Tight-fitting clothes prevent an adequate elimination of sweat, which, stagnating in the excretory ducts, can block its flow path. It is no coincidence that those who habitually wear tight-fitting clothes are more subject to the miliaria.
- Certain drugs. Some medicines, such as clonidine, beta-blockers and opiates, increase sweat gland activity and sweat production.
- Occlusive skin ointments and creams. The application of certain skin products can block the excretory ducts and prevent sweat from escaping. Sudamine, in these cases, also occurs when sweating is normal.
- An exaggerated clothing. Over-dressing or over-covering at night can cause you to sweat a lot and consequently cause a blockage of the excretory ducts.
RISK FACTORS
The individuals most easily subject to sweat are those who: live in areas with a hot-humid climate, such as the tropics; engage in activities (no matter whether sports or work) that make you sweat a lot; are overweight or obese; they have a habit of wearing more clothes than necessary; they are confined to a hospital bed due to an illness characterized by a high fever. To these risk categories are added infants and children, because they still have immature sweat glands, more prone to obstruction.
Symptoms and Complications
For further information: Miliaria Symptoms
The most characteristic sign of sudamine is a "skin 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 to the surface, passes through the dermis and epidermis.
Figure: crystalline sudamine.
Figure: sudamine in a child.
Figure: the epidermis and its layers. The epidermis, located in the most superficial part of the skin, has various layers of cells: in the deeper regions there are the cells of the basal layer and the stratum corneum; in the outermost regions, there are the cells of the horny, shiny and grainy layers.
The anatomical regions most affected by the skin rash are the areas covered by clothing; clothes, in fact, promote sweating and reduce the evaporation of sweat produced by the glands.
Depending on the layer of skin where the excretory duct of the sweat gland is blocked, sudamine can be divided into: crystalline sudamine (or miliaria crystalline), sudamine rubra (or miliaria rubra) and deep sudamine (or deep miliaria). Each type of sudamine is distinguished by its characteristic symptoms.
CRYSTALLINE SUDAMINE
Crystalline sudamine, or crystalline miliaria, is the most moderate and least severe form of sudamine: in fact, in most cases, it tends to resolve spontaneously within a few days.
It occurs when the tract of excretory duct passing through the outermost layers of the epidermis is blocked. The resulting rash does not produce any kind of itch and is characterized by papules and fragile white blisters filled with fluid.
Crystalline sudamine is the most common form among infants, however it can also affect adults.
SUDAMINA RUBRA
Sudamina rubra, or miliaria rubra, arises when the excretory ducts become blocked in the deeper layers of the epidermis. The skin rash that it causes can be characterized by:
- Small papules of red color
- Itching and stinging pain, similar to the prick of a thorn, at the level of the affected regions
- Reduced or completely absent sweating (anhidrosis) in the affected regions
Sudamine rubra affects adults more than children and represents the typical form of tropical climates and those who are bedridden due to a serious illness.
On some rare occasions, it can give rise to pustules; in this case, we also speak of pustular sudamine, or pustular miliaria.
DEEP SUDAMINA
Deep sudamine, or deep miliaria, is the most severe form of sudamine, 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, which is one of the deepest layers of the skin.
The skin rash may involve non-itchy, flesh-colored papules or a reaction very similar to goose skin.
The affected anatomical regions do not emit sweat (anhidrosis), so much so that the patient may be the victim of heat stroke, with dizziness, nausea and a rapid heartbeat.
WHEN TO SEE THE DOCTOR?
Most cases of sudamine resolve spontaneously, within a few days and without special treatments.
If, however, the symptoms do not show any improvement or if the affected areas unexpectedly become swollen, painful and purulent, it is advisable to contact your doctor and request an appointment, because it could be an infection.
Signs of an "infection in progress, which should attract the attention of the patient:
- Worsening of pain, swelling and redness in the area affected by the rash
- Sense of heat in correspondence with the exanthematous area (ie the area with the exanthema)
- Release of pus from papules or blisters
- Swollen lymph nodes in the armpits, neck or groin (when, of course, the rash appeared in these anatomical regions)
- Fever or chills
COMPLICATIONS
In addition to infections of bacterial origin, sudamine can also involve "another dangerous complication: heat stroke.
This, as anticipated, is typical of cases of deep miliaria (therefore it is rare), ie situations in which there is a "deep obstruction, at the level of the dermis, of the excretory ducts.
Symptoms of heatstroke are: drop in blood pressure (hypotension), dizziness, nausea, headache, and eventually a rapid heartbeat.
The people most prone to sweat-induced heat stroke are individuals who live in very hot geographic areas.
SUDAMINE IN CHILDREN
In infants and children, the characteristic skin rash is most common on the neck, shoulders, and chest, while it is less common on the armpits, elbows, and groin regions.
Diagnosis
No special tests are needed to diagnose Sudamine; in fact, an objective examination is sufficient, during which the doctor observes the skin rash and tries to discover its causes.
TRACKING THE CAUSES
To understand what caused the sudamine, the doctor asks the patient (or family members, if the patient was a newborn or 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
Sudamine, especially when it is mild, tends to resolve spontaneously within a few days.
To accelerate healing, it is very useful to limit all situations that favor the production of sweat or that prevent its elimination from the excretory ducts. The use of locally administered drugs is only foreseen in case of severe sweat and after an appropriate consultation doctor.
DO NOT SWEAT!
When you suffer from sweat, to heal faster, just avoid sweating too much for a few days. To succeed in this intent, it is a good idea:
- Avoid dressing too much, unless the temperature of the external environment makes it essential.
- Avoid dressing incorrectly when exercising.
- Improve the working or home environment, ventilating the area where you spend most of your time. This solution is particularly suitable for patients who periodically suffer from sudamine.
- Don't cover yourself up too much at night.
Once these steps are taken, the skin usually quickly returns to normal.
LOCAL DRUGS
The most serious rashes and at risk of complications are treated with locally administered drugs (N.B: local administration means that the drug is applied directly to the exanthematous area).
The most used medicines and preparations are calamine-based lotions, to soothe the itching sense, anhydrous lanolin, to prevent blockage of the excretory ducts and improve skin rashes scattered throughout the body, and corticosteroids, for papules and more severe pustules.
