In the hot summer, you should avoid going out during the peak hours to avoid sunburn.

Author: Ge Yongtong Children's Hospital Affiliated to Soochow University

Reviewer: Zhu Xueping, Chief Physician and Professor, Children's Hospital Affiliated to Soochow University

Nowadays, allergies have become an increasingly common chronic disease in people's lives, and people are paying more and more attention to allergies. On June 28, 2005, the World Allergy Organization (WAO) jointly launched a global initiative to combat allergic diseases (allergic diseases) with allergy agencies of various countries, and designated July 8 of each year as World Allergy Day, aiming to enhance the public's awareness of allergic diseases through education of doctors, patients and the public, and increase people's awareness of allergic diseases, so as to jointly prevent allergic reactions and allergic diseases. July 8, 2023 is the 19th "World Allergy Day", and the theme of this year is "Find the right allergens and prevent allergic diseases". I hope that through this small article, I can lead everyone to know more allergy knowledge points that are closely related to daily life. Let's follow us to circle the key points!

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1. What is allergy?

Allergy is a general term for a large category of diseases. It refers to an overreaction of the body's natural defense system (immune system) against infection to attack and eliminate some harmless substances, such as pollen, fur, food, drugs, etc. It is also called allergic reaction in medicine. People are prone to allergic symptoms after contact with allergens, such as redness, swelling, itching and pain of the skin, swelling and itching of the eyes, and in severe cases, nausea, vomiting, difficulty breathing, shock (clammy skin, pale complexion, restlessness, slow reaction and even confusion due to lack of blood supply). Therefore, allergic diseases are also called allergic diseases, which are mainly caused by the patient's excessive sensitivity and the production of a specific immunoglobulin E antibody in the blood that is allergic to a certain allergen. The main risk factors are low body immunity and poor biochemical environment.

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Among all kinds of allergic reactions, allergic dermatitis plays an important role. Allergic dermatitis is also called contact dermatitis. Its main cause is that the patient's skin comes into contact with irritating, toxic substances or allergens. With the arrival of hot summer, many people may find that "exposed" skin often experiences itching, flushing, swelling, etc. In severe cases, blisters may form, followed by erosion, residual pigmentation or hypopigmentation; conscious itching, burning or tenderness; systemic symptoms such as nausea, vomiting, dizziness, fever, etc. may also occur. So, how exactly does this happen?

2. “Allergy” or “sunburn”, don’t confuse them anymore!

We all know that in the hot summer, as the temperature rises, ultraviolet rays are also increasing. Ultraviolet rays are divided into short-wave ultraviolet rays (UVC), medium-wave ultraviolet rays (UVB) and long-wave ultraviolet rays (UVA). Sunburn, also known as solar dermatitis and ultraviolet allergy, is mainly caused by the skin being injured by the sun's medium-wave ultraviolet rays (wavelength 290-320 nm). Ultraviolet radiation can affect the function and survival of many cell types, causing a variety of cells in the dermis to release substances that mediate inflammation, causing acute inflammatory reactions. It is mainly divided into four types: photoallergic dermatitis, polymorphic solar dermatitis, acute solar dermatitis, and chronic solar dermatitis. Because there is a lot of strong light in summer, it often occurs in the hot summer season, and is common in the face, neck, arms, back of the hands and other parts.

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Typical "sun dermatitis" example picture:

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The occurrence of solar dermatitis is closely related to light intensity, exposure time, individual race, skin color, and weight. Infants and young children have incompletely developed skin and thin stratum corneum, which makes them more fragile and sensitive than adults. The whiteness, thinness, and tenderness of their skin have become their "little weaknesses", making them more susceptible to ultraviolet rays.

3. How to save baby’s sunburned skin!

I often hear some parents say: "The sun is shining brightly in the summer, so our baby can get some calcium from the sun." Some people do understand this, and appropriate sunlight can promote the synthesis of vitamin D and calcium absorption. However, little do they know that in the hot summer, the baby's skin is very fragile. Even if the baby is exposed to the sun for only a dozen minutes, the vitamin D in the body may not start to be synthesized, and the baby's skin may be sunburned. In this context, it is necessary to carefully balance the risks and benefits.

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If your baby's skin develops red spots, slight burning or stinging, and has a red nose tip or cheeks or mild peeling after sun exposure, it means that the baby has been mildly sunburned. At this time, you must avoid direct sunlight as soon as possible, return to indoors or a cool place, give the baby enough water, apply wet compresses to the sunburned area, cool the skin, calm the baby's emotions, and prevent further injury.

However, if the baby has large blisters, vomiting, chills, fever, etc., we should seek medical attention in time and receive more professional treatment and care. Or when parents are unsure about the baby's condition, they should not apply ointment casually to avoid aggravating the injury. It is a more appropriate choice to seek medical attention as soon as possible.

Sunburn, immunosuppression, photoaging, and photocancer are some of the most important adverse effects of solar radiation on humans. Children are a particularly vulnerable population because exposure to sunlight has more pronounced biological effects than adults. In addition, if appropriate measures are not taken, childhood is a critical period that promotes the development of photodamage and photocancer later in life. Therefore, prevention is of paramount importance. The best way to prevent sunburn is to go out during the "light" peak and avoid strong light exposure; do a good job of physical sun protection to reduce UV damage; drink plenty of water and supplement with sun-protective foods. Summer is here as scheduled, and parents must protect our babies, do a good job of daily protection, and stay away from UV radiation.

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References

[1]BRENNER M, HEARING V J. The protective role of melanin against UV damage in human skin[J].Photochem Photobiol, 2008, 84(3):539-49.

[2]KNUSCHKE P. Sun Exposure and Vitamin D[J]. Curr Probl Dermatol, 2021, 55:296-315.

[3]GARNACHO SAUCEDO GM, SALIDO VALLEJO R, MORENO GIMÉNEZ J C. Effects of solar radiation and an update on photoprotection][J]. An Pediatr (Engl Ed), 2020, 92(6):377.e1-377.e9.

[4]CHEN TC, CHIMEH F, LU Z, et al. Factors that influence the cutaneous synthesis and dietary sources of vitamin D[J]. Arch Biochem Biophys, 2007, 460:213–217.