Generality
Sweat dermatitis is an inflammation of the skin, which causes the rapid and sudden appearance of an itchy rash.
As the name suggests, the cause is the irritating action carried out on the skin by sweat . Not surprisingly, this type of dermatitis is more frequent in summer, a period in which we sweat more profusely. The areas of the body most affected are the armpit recess, the back, the abdomen, the chest and the groin.
The rash associated with sweat dermatitis tends to resolve spontaneously, but, if the dermatologist considers it necessary, it is possible to use cortisone-based creams or antihistamine drugs, to be taken orally. There are also several natural remedies that can help alleviate symptoms.
What's this
Sweat dermatitis is an inflammation of the skin caused by excessive transpiration.
This form of disorder occurs mainly with skin erythema, severe itching and a sense of heat, but, in the most severe forms, vesicles can also arise. The situation is aggravated in the case of particularly sensitive skin and an excessively hot-humid climate.
An episode of sweat dermatitis lasts from a few minutes to about an hour, then slowly regresses, until it disappears.
Sweating is one of the physiological methods used by our body to balance the loss and acquisition of heat. In other words, increased transpiration serves to control and regulate body temperature . Sweating usually manifests itself as a "background" activity, rarely visible.
The amount of sweat produced can be influenced by several factors, including intense exercise, high ambient temperature, fever, stress and emotional tension. Increased sweating can be a side effect of some drugs (such as morphine, antipyretics and thyroid hormone medicines) and alcohol abuse. Finally, copious transpiration can represent a symptom of diseases (such as hyperthyroidism and diabetes) and other non-pathological conditions (eg menopause, premenstrual period and pregnancy).
Causes
Sweat dermatitis is part of the large family of cholinergic urticaria . In this context, sweat is the specific irritant, but there are other factors that can contribute to triggering the eruption.
At the base of the typical symptoms of sweat dermatitis, there is a cutaneous hyperactivity, which depends on an excessive release of acetylcholine. In areas of the body where you sweat the most, this induces itchy crises, especially during the summer months : an excessively hot and humid climate, which favors sweating, is undoubtedly a cause of the problem.
Risk factors
Increased body temperature, a hot-humid climate and intense perspiration during sport are the main factors that predispose to sweat dermatitis. The latter is also found more frequently in those with very sensitive and reactive skin, such as children and people with atopic dermatitis.
However, there are other aggravating or predisposing factors that can promote inflammation.
The "triggers" of sweat dermatitis include:
- Physical exercise;
- Hot bath / shower or sauna;
- Temperature;
- Occlusive dressings;
- Spicy or very spicy food consumption;
- Emotional stress.
Athletes are particularly prone to developing sweat dermatitis, especially if the activity is carried out in a particularly heated environment and there is abundant sweating.
Furthermore, a greater probability of suffering from sweat dermatitis was observed in people suffering from generalized chronic urticaria, atopic dermatitis and allergic-type diseases (asthma, rhinitis, etc.).
Symptoms, signs and complications
Sweat dermatitis is a manifestation of variable intensity. Usually, this involves itchy "crises" lasting a few minutes.
The rash that characterizes sweat dermatitis is preceded by a series of prodromal symptoms. These include:
- Intense itching;
- Tingling;
- Burning or stinging;
- Heat sensation;
- Reddish patches (similar to those that appear in the case of sunburn).
In the body area involved, then, sweat dermatitis causes the onset of numerous wheals, detected with respect to the skin plane. Sometimes, these small swellings can join together to form a more or less extensive edema.
In the more severe forms, blisters (1-4 mm) may appear, surrounded by a reddish halo. Less often, patients experience systemic symptoms, such as headaches, hypersalivation, palpitations, fainting, hypotension, shortness of breath, abdominal cramps, vomiting and diarrhea.
Where it occurs
Sweat dermatitis can occur in any part of the body.
In most cases, however, the rash affects the areas rich in sweat glands : armpits, hollows of the arms and knees, chest, lumbar area of the back, abdomen, groin area, under the breast, but it is not excluded not even the scalp.
How long does an episode of sweat dermatitis last?
Usually, the symptoms of sweat dermatitis arise quickly (within 3-10 minutes from the start of sweating) and remain from 30 minutes to an hour or more, before resolving. The average duration of an episode is about 80 minutes.
Possible consequences
After resolving the sweat dermatitis episode, the skin sites involved in the skin reaction may be refractory to stimuli for a few hours. The appearance of the skin returns to normal as soon as the wheals disappear.
Following the appearance of sweat dermatitis, irritation leads to a persistent itching. Not resisting the urge to scratch can worsen the situation and trigger a very obvious skin alteration, causing redness, burning, peeling and swelling.
Diagnosis
The diagnosis of sweat dermatitis is formulated by the dermatologist, based on the history and physical examination. Only in complicated or atypical cases, the doctor can proceed with other diagnostic investigations (eg microbiological culture or biopsy).
Other conditions can simulate sweat dermatitis including allergic reactions, eczema, bacterial and fungal infections.
Therapy
The symptoms of sweat dermatitis tend to resolve spontaneously, without the use of specific therapies.
To prevent an episode, situations that trigger the inflammatory process should be avoided as far as possible. Clearly, in many cases it is difficult to stop sweating, especially if the weather is very hot and a sport is practiced. However, there are some precautions that can limit the activation of sweat dermatitis.
If exercise is part of the daily routine, for example, it may be indicated to avoid clothing made with synthetic fibers during the activity. It should also be considered that prolonged contact with sweat is responsible for more intense and annoying events; for this reason, rapid cooling can prevent an attack.
In its milder forms, inflammation can be treated simply with:
- Chamomile wraps (refreshing and soothing);
- Sage packs (counteracts excessive sweating and has disinfectant properties);
- Rice starch baths (soothes skin redness and softens the skin);
These natural remedies can help alleviate the symptoms of sweat dermatitis.
With regard to drug therapies, the dermatologist can indicate, if deemed appropriate, the application of cortisone- based creams or the use of antihistamine drugs.
Some advice
To best deal with sweat dermatitis, it may be useful to follow some trivial, but important, tricks:
- In order not to compromise proper healing, the vesicles should never be pierced ; this behavior risks aggravating the inflammation, therefore it is necessary to wait for these lesions to be absorbed spontaneously.
- For daily hygiene, use delicate and non-aggressive products, free of alcohol, preservatives, perfume or petrolatum; detergents must be as natural as possible and neutral in formulation. This rule also applies to deodorants.
- Avoid applying talc, which can help to clog pores, inhibiting proper transpiration of the skin.
- Wear comfortable clothes, made of natural fabric, such as cotton, linen and silk, as they facilitate perspiration. Instead, synthetic fibers and clothes that are too tight are to be avoided, as they increase sweating and can promote irritation, as a result of rubbing with the skin.
- Pay attention to proper hydration, drinking at least two liters of water a day to rebalance the right amount and the loss of fluids that can occur during excessive sweating.
- Follow a balanced and healthy diet, avoiding all those foods that contribute to exacerbating the inflammatory process, such as spicy and fatty foods, sausages, fried foods and spicy dishes. For the same reason, alcoholic beverages should not be abused. In case of tendency to sweat dermatitis, foods rich in fiber, vitamins and mineral salts (whole grains, vegetables and fresh fruit) should also be preferred, also to replenish the fluids lost through excessive transpiration.
