Allergic contact dermatitis is an inflammatory lesion of the skin that occurs as a result of direct contact of the skin with an optional allergen (a substance that does not cause allergic reactions in healthy people).
Manifestations of the disease are found after some time after contact with the allergen (after a single interaction with a strong stimulus or after repeated contact with the middle stimulus). Often this time is about 14 days. Thus, the basis of this pathology is a delayed-type allergic reaction.
There is an allergic dermatitis in people with a genetic predisposition to the development of this disease and altered immunity. That is, the disease is inherited.
Causes of allergic contact dermatitis
The cause of the development of allergic contact dermatitis on the face and other parts of the body is a close and sufficiently long contact of the allergen with the skin. After the first interaction, the phase of sensitization begins - the formation of specific immunity against the allergen. The period of time for which sensitization of the organism develops and an allergic reaction develops is determined by how strong the stimulus is. It is also important duration of exposure to the allergen and the state of the human body (malfunctions of immunity, a tendency to allergies , etc.).
The risk of allergic dermatitis is a violation of the integrity of the skin. Therefore, this disease in many cases develops as a professional, when a person has contact with substances that can act as allergens, and periodic damage to the skin during labor activity.
To date, there are over three thousand substances known to cause the development of allergies. Basically, these are various washing and cosmetic products, dyes, some metals and their salts, rubber, preservatives, medicines, as well as substances of plant origin.
Allergic contact dermatitis - symptoms in adults
The clinical picture of the disease resembles the acute stage of eczema. A typical symptom of allergic dermatitis is a change in the skin localized at the site of skin contact with the allergen and somewhat outside the range of the stimulus. The defeat center always has clear boundaries.
In the beginning, reddening of the skin and a slight swelling. Further on this site there are multiple inflammatory papules filled with liquid and passing into the stage of the vesicles. Then the bubbles begin to burst and empty, leaving permanently wet erosion. When healing, they are covered with small scales and crusts. After recovery, scarring does not remain, if there was no secondary
Thus, the clinical picture of allergic contact dermatitis has three stages:
- erythematous stage;
- vesiculobullus stage;
- necrotic stage.
All these changes on the skin are accompanied by a constant intense itching, which causes severe pain to the patient and disrupts daily life. Itching leads to scratching and the appearance of secondary skin lesions.
With continued contact of the allergen against the background of the already appeared allergic reaction, chronic allergic dermatitis can develop. This form is characterized by blurred boundaries of skin changes and the spread of lesions to areas of the skin that do not come into contact with the allergen.