Allergic skin diseases have various causative factors, and progress with various symptoms such as pruritus, redness (rash) and swelling. It is a reaction of the immune system.
Atopy: It is defined as the individual’s predisposition to developing allergic reaction.
- Atopic Dermatitis (Eczema): Dry skin, itching and redness are seen. It is a recurrent and chronic condition. Its different manifestations are seen infancy, childhood and adolescence.
- Urticaria (Hives): Suddenly edematous, erythematous plaques of different sizes emerge on the skin. 20 minutes to 3 hours later they disappear without leaving a trace. If it disappears within 6 weeks it is called acute, if it persists longer than 6 weeks it is termed as chronic urticaria.
This allergic skin disease develops after contacts with detergents, topical medications,cosmetics, plants, exposure to sun, hot and cold objects with manifestations of skin redness, edema then drying and scaling. Two types of contact dermatitis are seen:
- Allergic Contact Dermatitis: Allergic response of the immune system to the substance that is exposed to the skin. It is seen 24-48 hours after the contact.
- Irritant Contact Dermatitis: Its effects are seen on the area of contact. The most common causative agents are detergents and it is usually seen on hands.
For the diagnosis usually patch test is used. In this test the most frequently encountered allergenic substances are applied on the back of the patient in a hypoallergenic adhesive tape, and 24 hours later the tape is removed. If the responsible allergenic substance can be detected, then as a basic principle you should avoid contact with this substance.