Itchy~itchy~itchy~ Summer is related to "prickly heat"

It's not until the rain that spring has gone, and it's not until the sun clears that summer has deepened. After the days of wearing random clothes, it seems like we have entered the height of summer. As soon as the sun comes out, people sweat profusely. It's fine if you don't sweat, but once you sweat, some people will find itchy papules on their necks, armpits, and elbows, and they turn red when you scratch them. At this time, everyone will say: This is heat rash.

What kind of skin disease is this "prickly heat" that we have heard about since childhood and which no one, from children to adults, can get rid of?

Image source: soogif

1. Heat rash: It’s all caused by sweat

Prickly heat is a common skin disease, also known as heat rash or seborrheic dermatitis. The cause of prickly heat is simple: sweat is secreted by sweat glands and discharged from the body through the sweat gland ducts. If this "sweat duct" is blocked, it will cause prickly heat, that is, the appearance of prickly heat. Therefore, prickly heat usually occurs in hot and humid weather or high temperature environments, especially in summer. Then why would the sweat gland ducts be blocked?

It turns out that in a hot and humid environment, a large amount of sweat is not easy to evaporate. It will stay on the body surface and soak the skin to make it swollen, which will cause the sweat ducts to narrow or become blocked. In addition, skin cells and other debris can also block the sweat ducts. When the sweat is retained in the sweat ducts, the sweat ducts may rupture when the pressure increases, and the sweat will seep into the surrounding tissues and cause the disease.

Image source: Paixin Creative

2. Both white prickly heat and red prickly heat are prickly heat

Depending on the location of sweat duct damage and sweat overflow, prickly heat is clinically divided into four types: white prickly heat, red prickly heat, pus-filled prickly heat and deep prickly heat.

Before introducing these four types of prickly heat, we must first popularize the structure of our human skin. The skin is divided into the epidermis and dermis, with the epidermis on the outside and the dermis on the inside. The epidermis is divided into the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale from the outside to the inside. Further down are the papillary layer and reticular layer belonging to the dermis. The sweat glands are composed of a secretory part and a ductal part. The secretory part is located in the deep dermis and subcutaneous tissue. The secretory part directly continues upward into the duct. The duct of the sweat gland is thinner and ascends from the deep dermis. After entering the epidermis, the duct rises in a spiral shape and directly opens into the sweat pores on the surface of the skin.

Human skin structure丨Source: Yitu.com

Next, let's introduce prickly heat, also known as red miliaria. This most common type is more common in young children and people working in high temperatures. It is caused by the accumulation of sweat in the sweat ducts of the epidermal stratum spinosum. Prickly heat often occurs in the armpits, elbows, neck and other parts, and is often accompanied by the appearance of papules. Of course, the most obvious symptom is erythema plus itching (or burning), which can be aggravated by sweating. Therefore, the symptoms mentioned at the beginning of the article are actually prickly heat.

White prickly heat, also known as crystal miliary rash, is more likely to occur in newborns or bedridden people with weak constitution and excessive sweating. It is caused by the overflow of sweat in the stratum corneum or the sweat ducts below the stratum corneum. Unlike red prickly heat, white prickly heat usually occurs on the trunk and skin folds, manifesting as a batch of needle-sized blisters that are transparent, like water droplets, and easy to rupture. It also does not cause itching and erythema like red prickly heat.

Image source: Internet

On the basis of miliaria rubra, scratching causes skin damage, bacteria invade and cause infection (commonly known as suppuration), which turns into purulent prickly heat. Therefore, the characteristic of purulent prickly heat is the appearance of needle-sized, superficial pustules on the basis of miliaria rubra.

Deep miliary rash, also known as deep miliary rash, mostly affects people in tropical areas who have repeated episodes of miliary rash. It occurs when sweat ducts at the junction of the epidermis and dermis rupture and overflow, and the epidermal sweat ducts are damaged by repeated episodes of miliary rash, causing sweat to be blocked in the dermis. It often occurs in the neck, trunk, and limbs. It manifests as hard papules with dense skin lesions that are consistent with sweat pores and are red or the color of normal skin.

3. Treat the unbearable pain and itching

Heat rash is usually harmless and will go away on its own when the skin is dry and cool. So, when the symptoms of heat rash are mild, you can start with some basic treatments. For example, keep the affected area cool and dry, use a fan or air conditioner to cool the body, or take a warm bath every day and let the skin air dry. Wear loose, breathable cotton clothing as much as possible, and avoid strenuous exercise or prolonged exposure to high temperatures that cause excessive sweating.

If you experience mild itching or pain from the rash, you can also apply a wet towel or an ice pack (wrapped in a towel) to the affected area.

Image source: Yitu.com

However, the above methods are only applicable when the prickly heat does not subside for several days, or the area around the prickly heat is painful, swollen, or red, or even worse day by day, and some prickly heat is infected or festered, and symptoms such as fever or chills appear, then don’t think about applying dry ice anymore, but go to the dermatology department of the hospital to ask a doctor. At this time, the doctor will make a diagnosis based on the time of appearance of the skin lesions, the location and size of the skin lesions, and whether they are accompanied by itching and pain. If drug treatment is necessary, the doctor may prescribe some topical antipruritic agents or ointments, and use them in conjunction with some oral medicines for clearing away heat and detoxification.

4. “I just love to spoil my kids”

Here we have to talk about a question that parents are more concerned about: Why are children more likely to get prickly heat than adults?

First of all, it is because children's sweat glands are immature, especially in infants under 1 year old, whose sweat gland system is not fully developed. This causes them to have a weaker sweating function than adults, weaker body temperature regulation ability, and are prone to excessive sweating in high temperature environments, thus increasing the risk of prickly heat.

Image source: Paixin Creative

Secondly, children's skin is relatively delicate and more fragile than that of adults. Their stratum corneum is thinner, and the skin barrier function is not perfect, which makes them easily susceptible to external stimuli. When children are in a hot and humid environment, such as wearing too many clothes or wrapping too tightly on hot days, the high temperature and the friction between the clothes and the skin make the skin easily damaged, thus causing prickly heat.

Some parents are overly concerned about cleanliness and disinfection when bathing their children, using too much soap and detergent, or using inappropriate cleaning products, or bathing too frequently, which may damage the natural protective layer of children's skin. This will dry out the skin, cause acid-base imbalance, and increase the risk of children suffering from prickly heat.

Image source: Paixin Creative

Finally, clothing that is in close contact with the skin can also cause prickly heat: some clothing and diapers made of synthetic materials have poor breathability, which hinders air circulation, causing children to sweat easily in high temperatures and the sweat cannot evaporate in time, increasing the possibility of prickly heat.

Therefore, when children get prickly heat, it is important to take preventive measures. For example, maintain appropriate indoor temperature and humidity, avoid excessively hot and humid environments; choose natural fiber clothing that is breathable, soft and comfortable, and avoid wearing too many layers; when bathing children, use warm water and mild cleaning products, and avoid frequent washing with soap. At the same time, pay attention to keeping the skin clean and dry, and use appropriate skin care products on areas of the skin that are prone to friction, such as applying an appropriate amount of non-irritating talcum powder.

Image source: Yitu.com

If children have prickly heat, they should try to avoid scratching, keep the skin clean, and try conservative treatment. If the prickly heat persists or becomes more severe, you should see a doctor immediately.

Audit expert: Huang He

Source: Chongqing Science and Technology Museum

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