Simple contact dermatitis

Simple contact dermatitis (synonyms: contact dermatitis, artificial dermatitis) is characterized by the occurrence of a lesion exclusively at the site of exposure to an irritating factor, the absence of sensitization and a tendency to disseminate and spread along the periphery of the lesion.

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Causes contact dermatitis

Contact dermatitis occurs when the skin comes into contact with irritants or allergens. Some of the most common causes of contact dermatitis include:

1. Chemicals: Contact with various chemicals can cause skin irritation. These may include detergents, disinfectants, oils, solvents, acids, alkalis and other chemical compounds.
2. Metals: Contact with metals such as nickel can cause allergic contact dermatitis. Nickel is often found in jewelry, bracelets, and watch bands.
3. Plants: Some plants contain substances that can irritate the skin. These include trees, such as poison oak and poison ivy, and some plants in the poppy family, such as poppy and jaundice.
4. Medicines: Some medicines, especially topical preparations, can cause contact dermatitis. This may be due to individual sensitivity to the components of the medicine.
5. Cosmetics: Some cosmetics, including creams, lotions, makeup, and perfumes, may cause irritation or allergic contact dermatitis.
6. Metal Clothing Parts: Contact with metal buttons, zippers and buckles on clothing may cause skin irritation.
7. Food: Some people may experience allergic reactions when exposed to certain foods.
8. Sun: This can cause photodermatitis, where the skin becomes sensitive to sunlight after contact with sunflower oil.
9. Other allergens: Contact dermatitis can also be caused by contact with various allergens such as rubber, chemicals, and even animal skin.

These are just a few examples of causes of contact dermatitis. It is important to note that skin reactions vary from person to person, and what causes dermatitis in one person may not cause it in another.

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Pathogenesis

Simple dermatitis occurs due to the action of chemical (concentrated acids, alkalis), physical (high or low temperature, radiation exposure), mechanical (pressure, friction) and biological factors. It is known that the skin as an organ occupies an exceptional place in the manifestations of immediate and delayed hypersensitivity reactions. In addition, according to a number of authors, the skin is an immune organ, which is confirmed by the presence of lymphoid centers in it, which are involved in hypersensitivity reactions and participate in the formation of foci of immune inflammation in it. Contact allergic dermatitis is based on a type of delayed hypersensitivity called contact hypersensitivity. Contact allergic dermatitis can have an acute, subacute and chronic course.

A number of studies have described the morphology of allergic contact dermatitis at different stages of its development, caused in guinea pigs by applying an obligate allergen, 2,4-dinitrochlorobenzene (DNCB), to the skin. It has been shown that in the primary contact reaction, developing 24 hours after the application of DNCB, destructive changes in the epidermis, sometimes necrosis and its detachment, are observed. In the dermis, there is an inflammatory reaction with vascular damage of a destructive nature and perivascular infiltrates, in which, in addition to mononuclear cells, neutrophilic granulocytes and tissue basophils with degranulation phenomena are found.

In allergic contact dermatitis (on the 15th day after repeated application of the allergen), morphological changes were of a different nature. In the epidermis, acanthosis was determined, expressed to a greater or lesser extent depending on the severity of the process, inter- and intracellular edema, and exocytosis. In the dermis, there was hypertrophy of the endothelium of the microcirculatory bed vessels, narrowing of their lumens, perivascular infiltrates consisting of lymphoid cells, macrophages, active fibroblasts, among which, as a rule, tissue and hematogenous basophils were found.

Skin tests are used to diagnose various types of contact dermatitis in humans. Application of an allergen in allergic contact dermatitis in humans causes alterative changes in the epidermis, vasodilation, and extravasation of mononuclear elements from them into the dermis 3 hours after application. Basal spongiosis is formed 8 hours after application, and after 12 hours and later, spongiosis reaches the upper layers of the epidermis with the formation of blisters.

Histological diagnosis of contact allergic dermatitis in humans is very difficult. This is due to the fact that biopsy is usually performed several days after the detection of dermatitis, at the height of its development, when a non-specific inflammatory reaction is seen. It is also difficult to distinguish between phototoxic and photoallergic dermatitis.

Histogenesis of contact dermatitis

In the development of sensitization in animals, three phases are distinguished based on the clinical and morphological picture of the skin:

1. primary contact reaction;
2. spontaneous inflammatory reaction, or inflammation reaction;
3. inflammatory reaction to the permissive application of an allergen (skin test), simulating allergic contact dermatitis.

Primary contact reaction is morphologically expressed as non-specific inflammation. However, the appearance of activated lymphocytes, detection of contacts between macrophages and lymphocytes on electronograms may indicate the initial signs of sensitization development. Necrosis in the epidermis and changes in capillaries during this period can be assessed as a result of the toxic effect of DNCB.

The spontaneous inflammatory reaction has features of immune inflammation, as evidenced by the appearance of activated lymphocytes, immunoblast-type cells, plasmablasts and plasma cells in the infiltrate, as well as a high content of basophils, accompanied by basophilia in the blood.

In the inflammatory reaction to the application of a resolving dose of DNCB, the infiltrate was composed of lymphocytes, macrophages, active protein-synthesizing cells, and basophils with signs of degranulation. Such morphology of the cellular infiltrate in the skin test is characteristic of contact allergy and other forms of delayed-type hypersensitivity. However, the presence of basophils in the infiltrate, participating in IgE-dependent reactions, also indicates the role of immediate-type hypersensitivity in the development of allergic contact dermatitis.

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Symptoms contact dermatitis

According to the course of the skin pathological process, acute and chronic simple dermatitis are distinguished. Acute dermatitis is characterized by bright redness and swelling of the skin, small nodules and blisters are often observed, sometimes - weeping, scales and crusts. In some cases, larger blisters and even blisters appear, and sometimes necrotic changes. Patients usually experience a feeling of heat, burning, itching, and sometimes pain.

Chronic dermatitis occurs with chronic pressure and friction, the force of which is relatively small. In this case, the skin thickens, lichenification and infiltration occur due to thickening of the epidermis and hyperkeratosis. For example, various types of ionizing radiation (sun rays, X-rays, alpha, beta, gamma rays, neutron radiation) contribute to the development of acute or chronic radiation dermatitis. Depending on the dose, penetrating ability of radiation and individual sensitivity, radiation dermatitis can manifest itself as erythema (with a peculiar purple or bluish tint), temporary hair loss, bullous reaction against the background of intense hyperemia and edema. In these cases, the process ends with skin atrophy, persistent alopecia, the formation of telangiectasias, pigmentation disorders - "motley, X-ray skin", a necrotic reaction may develop with the formation of difficult-to-heal erosions and ulcers.

Repeated irradiation of the skin with "soft" X-rays in relatively low doses and exposure to radioactive substances lead to the development of chronic radiation dermatitis. In the lesion, dryness, thinning of the skin, loss of elasticity, the presence of telangiectasias, depigmented and hyperpigmented areas, onychodystrophy, itching, i.e. the clinical picture of poikiloderma, are observed. Chronic radiation damage to the skin contributes to the formation of papillomas, hyperkeratosis, warty growths, ulcers in the damaged areas, which have a tendency to malignant degeneration.

Chemical simple contact dermatitis occurs due to the action of strong acids and alkalis, alkali metal salts and mineral acids, etc. Such dermatitis occurs acutely, occurs against the background of necrosis with the formation of a scab, after the separation of which an ulcer is discovered.

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Stages

Contact dermatitis has several stages of development, which may vary depending on the specific case and individual characteristics of the organism. The main stages of contact dermatitis include:

1. Contact (exposure): At this stage, the skin comes into contact with the irritant or allergen. This could be shoes, jewelry, cosmetics, chemicals, and other factors. There may not be any visible symptoms at this stage, but the process of skin exposure begins.
2. Development of symptoms: Symptoms of contact dermatitis begin to appear after contact with an irritant or allergen. This usually manifests as itching, redness, swelling, or rashes on the skin. This stage can last for several hours or days.
3. Acute stage: At this stage, the symptoms become more pronounced and intense. The skin may become irritated, reddened, covered with fluid-filled blisters, and cracks and ulcers may form. The symptoms may be accompanied by pain and itching.
4. Subacute contact dermatitis: If contact with the irritant continues or is not eliminated, the condition may progress to this stage. At this stage, symptoms become less severe but are still present.
5. Chronic stage: If dermatitis continues to develop over a longer period of time, it may progress to the chronic stage. Symptoms may be less severe, but they are often persistent and the skin may be thicker, rougher, and more coarse.
6. Remission and exacerbation: Contact dermatitis may have periods of exacerbation, when symptoms become worse, and periods of remission, when symptoms decrease or disappear.

It is important to note that the symptoms and stages of contact dermatitis can vary depending on the individual's characteristics and the type of irritant.

Forms

Contact dermatitis can take several forms, depending on what type of irritant causes the skin to react and what symptoms predominate. The main forms of contact dermatitis include:

1. Allergic contact dermatitis: This form of dermatitis develops as a result of an allergic reaction to a specific substance called an allergen. The allergen can be something that the skin comes into contact with, such as nickel, latex, plants, or certain cosmetics. Symptoms include itching, redness, swelling, and rashes on the skin.
2. Irritant contact dermatitis: This form of dermatitis is caused by skin irritation from chemicals such as acids, alkalis, solvents and many others. The main symptom is redness and inflammation of the skin. This type of dermatitis is most often associated with occupational activities where the skin is frequently in contact with irritants.
3. Phytodermatitis: This type of contact dermatitis develops as a result of contact with plants containing photosensitizing substances. After contact with such plants, the skin becomes sensitive to ultraviolet rays, which can cause sunburn. Typical plants that cause phytodermatitis are shepherd's purse, poison ivy, citrus fruits, and others.
4. Pharmacodermatitis: This type of contact dermatitis is associated with the use of drugs that cause an allergic reaction on the skin. The drugs may be in the form of ointments, creams, lotions or patches.
5. Metallodermatitis: This form of dermatitis is associated with contact with metals such as nickel or chromium, which are often used in jewelry, clothing zippers, or even medical implants.
6. Other forms: There are many other forms of contact dermatitis, including alcohol dermatitis (caused by exposure of the skin to alcohol solutions), soap dermatitis (when cleansers cause a reaction), and others.

It is important to note that symptoms and treatment of contact dermatitis may vary depending on its form and cause. Diagnosis and determination of the form of dermatitis play a key role in developing effective treatment and prevention.

Diagnostics contact dermatitis

Diagnosis of contact dermatitis typically involves the following steps:

1. Medical history: Your doctor will talk to you about your symptoms, when and where the rash or skin irritation occurred. He or she will also ask about your professional and daily activities to see if any factors or substances may be causing the reaction.
2. Physical examination: The doctor will carefully examine the skin to assess the nature of the rash, its location, the degree of inflammation, and other characteristics. This will help the doctor determine whether it is contact dermatitis and what type it is.
3. Patch testing: If allergic contact dermatitis is suspected, patch testing may be performed. In this test, special patches with potential allergens are applied to the skin. After a few days, the skin's reaction to the patches is assessed to determine which allergen you may be allergic to.
4. Ruling out other causes: To help clarify the diagnosis, your doctor may rule out other possible causes of your rash or skin inflammation, such as infections, other skin conditions, or allergic reactions to medications.
5. Laboratory tests: Sometimes laboratory tests may be needed to rule out infectious causes of symptoms.
6. Diagnosis of the form of dermatitis: The doctor can determine the form of contact dermatitis (allergic, irritant, etc.) based on clinical data and test results.

Diagnosis requires careful analysis of symptoms, history, and clinical data. Once an accurate diagnosis is made, the doctor can recommend appropriate treatment and precautions to prevent recurrence.

Treatment contact dermatitis

Treatment of contact dermatitis depends on its form (allergic or irritant), severity and specific symptoms. It usually includes the following aspects:

1. Avoidance of the irritant: An important part of treating contact dermatitis is identifying and avoiding the irritant or allergen that caused the skin reaction. This may include changing your occupation, changing cosmetics, jewelry, or clothing, and using protective equipment.

2. Treatment of symptoms: The following methods may be used to relieve symptoms of contact dermatitis:

   • Topical treatment: Using ointments, creams, or lotions containing hydrocortisone or other corticosteroids may help reduce inflammation and itching.
   • Antihistamines: Taking antihistamines by mouth can help reduce itching and inflammation.
   • Dry dressings: For rashes with fluid blisters or ulcers, applying dry dressings may be helpful to prevent infection.

3. Treatment of acute manifestations: In cases of acute and severe skin inflammation, your doctor may prescribe a short course of corticosteroid medications to reduce symptoms.

4. Treatment for allergic contact dermatitis: If your dermatitis is caused by an allergy to a specific allergen, treatment may include hyposensitization, in which you gradually introduce small doses of the allergen to reduce your sensitivity to it.

5. Practicing good hygiene: Regular skin care with mild cleansers and moisturizers can help reduce dryness and irritation of the skin.

6. Relapse Prevention: Once acute symptoms have subsided, it is important to continue avoiding contact with the irritant and taking preventive measures to prevent relapse.

If symptoms of contact dermatitis do not improve with home treatment or worsen, it is important to see a doctor or dermatologist. The doctor may recommend more intensive treatment or additional tests to determine the cause and type of dermatitis.

The treatment depends on the severity of the inflammatory phenomena. In mild cases, it is sufficient to prescribe powders, corticosteroid ointments or antipruritic agents (Fenistil gel, 2% menthol ointment, etc.). In the presence of blisters, the surrounding skin areas are cleaned with 1% boric alcohol, and then the blisters are punctured. The affected areas are lubricated with aniline dyes. In severe cases of simple contact dermatitis (tissue necrosis), patients are hospitalized in specialized hospitals.

Prevention

Prevention of contact dermatitis includes a number of measures and recommendations that will help prevent irritation and allergic reactions on the skin. Here are some basic prevention tips:

1. Avoid contact with known irritants: If you have known allergens or irritants, avoid contact with them. This may include using alternative products, avoiding jewelry that contains metals that cause allergies (such as nickel), etc.
2. Use protective equipment: If you are working with chemicals or other irritants, be sure to use protective equipment such as gloves, goggles, and masks.
3. Mild detergents: Use mild and hypoallergenic detergents for skin and clothing. Avoid harsh soaps and disinfectants that can dry out the skin.
4. Moisturize your skin: Moisturize your skin regularly with hypoallergenic moisturizers. Dry skin is more prone to irritation.
5. After showering or bathing: After bathing, gently dry your skin with a towel, without rubbing it too hard. Then apply moisturizer.
6. Change your clothing: If you notice that certain clothing items are causing you irritation, consider switching to fabrics that are less harsh on your skin.
7. Sun protection: If you have a sun allergy (photodermatitis), use sunscreen and wear protective clothing when exposed to the sun for long periods of time.
8. Patch testing: If you suspect allergic contact dermatitis, have patch testing done under the guidance of a dermatologist to check for allergic reactions.
9. Follow the instructions for using cosmetics: When using cosmetics, follow the manufacturer's instructions and pay attention to the composition of the products.
10. Consult your doctor: If you have a tendency to have allergic skin reactions or are at risk for contact dermatitis, discuss this with your doctor or dermatologist. They can provide additional advice and conduct any necessary tests.

Following these steps will help you reduce your risk of developing contact dermatitis and maintain healthy skin.

Forecast

The prognosis for contact dermatitis depends on several factors, including its type, severity, duration and effectiveness of treatment, and how well you avoid contact with irritants. In most cases, contact dermatitis is treatable and has a good prognosis. However, there are some general aspects to consider:

1. Acute contact dermatitis: In cases of acute contact dermatitis associated with recent contact with an irritant, the prognosis is usually good. Once contact with the irritant is avoided and appropriate treatment is given, symptoms may improve rapidly.
2. Chronic contact dermatitis: People with chronic contact dermatitis may have a poorer prognosis, especially if the cause of the irritation is difficult to identify or avoid. In such cases, long-term treatment and measures to reduce the risk of relapse may be needed.
3. Allergic contact dermatitis: The prognosis for allergic contact dermatitis may depend on the allergen and the degree of sensitivity to it. Once the allergen is identified and contact with it is avoided, symptoms may improve. For some allergies, the prognosis may be more complex and long-term symptom management may be necessary.
4. Following preventive recommendations: It is important to follow your doctor's recommendations and take preventive measures to prevent recurrence of contact dermatitis.
5. Maintaining Healthy Skin: Regular skin care and moisturizing will help maintain healthy skin and reduce the risk of recurring dermatitis.

If you have contact dermatitis, it is important to see a doctor or dermatologist for an accurate diagnosis and appropriate treatment. With proper advice and preventive measures, most people can successfully manage their condition and have a good prognosis.

Some classic and authoritative sources that might contain information about simple contact dermatitis are:

1. Fisher's Contact Dermatitis is a book edited by Rishi P. Anand, 2019. It is the authoritative guide to contact dermatitis, including the latest scientific evidence and clinical aspects.
2. "Contact Dermatitis" is a book edited by Juliette M. Fontenay and John L. Bollard, 2019. This book covers a wide range of aspects of contact dermatitis, including pathogenesis, clinical manifestations and treatment methods.
3. "Irritant Dermatitis: New Insights" is a 2020 article in the journal Dermatitis by Michael Bove and James S. Taylor. This article provides new scientific research and insight into the irritant of contact dermatitis.
4. "Occupational Contact Dermatitis" is a book edited by Michael Bove and Peter J. Fries, 2019. It focuses on occupational contact dermatitis and includes case reports and studies.
5. "Textbook of Contact Dermatitis" - edited by Angel P. Fonseca and Stefan S. Yakimoff, 2001. This book is a classic resource that includes extensive knowledge about contact dermatitis.

References

1. Khaitov R.M., Ilyina N.I. - Allergology and immunology. National guidelines, 2009
2. Khaitov, R. M. Allergology and immunology / ed. R. M. Khaitova, N. I. Ilina - Moscow: GEOTAR-Media, 2014