Skin allergy rash can have different manifestations depending on the agent causing it, and more importantly, on the path of the allergen to the body. The most common type is urticarial, or hives, which is itchy, light-red bumps or plaques. Here you can find a brief overview of the causes, differential diagnostics, and treatments for this skin-damaging condition.
Any allergen from the external environment can cause an allergic reaction of the skin, either by close contact with the skin, by inhalation, or ingestion. Some of the most well-known allergens include tree and grass pollen, clothes made of synthetic materials, components of detergents, fabric softeners, and skin care products. Some medications can also cause severe allergic reactions of the skin. Allergy can also be caused by biological factors, such as bacteria, viruses, or more commonly insect bites and contact with animal skin.
By the way, there is even a pseudo-allergic reaction, caused by exposure to sunlight (solar urticaria), cold and physical activity (cholinergic urticaria), or psychological stress with symptoms which looks very similar to the “true” allergic reaction.
There are several types of skin allergy manifestations. The main features usually include the sudden appearance of hard, round or oval-shaped, pink papules called urticaria. The skin often becomes itchy and commonly associated with swelling of the affected regions. Sometimes they develop fast and can be separate or confluent, covering large areas of the skin with other joined symptoms, such as breathing difficulties and/or swelling of the soft tissues of the face and neck called angioedema. In the most severe cases, the anaphylactic shock might develop, which could be accompanied by a serious drop in blood pressure, in addition to the described issues.
Duration of these symptoms varies depending on the contact with the allergen. Acute urticaria lasts from 1 day to 6 weeks, and it disappears spontaneously or with therapy. If the allergy skin rash persists more than 6 weeks, then it is called chronic urticaria. Chronic urticaria can last for years, and while the cause of acute urticaria is often easy to uncover, the cause of chronic urticaria is usually unknown (also called idiopathic). In these cases, it’s better to consult a dermatologist to decide on the appropriate treatment and lifestyle changes.
Skin allergy is usually diagnosed on the basis of the patient interview and physical examination of the skin. The allergy could be identified through patch testing, which involves localized exposure to the set of typical allergens and monitoring of the skin reaction. There are also immunological tests which detect the concentration of specific antibodies in the blood responsible for the allergic reaction.
For mild cases of acute urticaria, it is often enough to remove the causative factor, and the allergic skin reaction will resolve spontaneously. In some cases, topical or oral antihistamine medications can be used to eliminate the symptoms, primarily to decrease itching. In more severe cases, antihistamines are necessary to block the progress of the skin changes. Corticosteroids are used to minimize the reaction of the immune system to the allergen and to lower the swelling of the skin and soft tissues. Adrenaline shots are used in some extreme cases of breathing difficulties and anaphylactic shock.
For chronic urticaria, the multidisciplinary approach is required. Different specialists, such as a dermatologist, immunologist, and occupational medicine specialist should be involved in its assessment and management.
For some allergies with known causes, there are vaccines, which can desensitize the immune system against the specific allergen, and therefore decrease the allergic reaction. Scientists are currently developing more advanced vaccines, which can help with any allergy, regardless of the responsible allergen.
If you’re suffering from skin allergy and want to get a qualified assessment of your skin condition, we welcome you to schedule an appointment at one of our three convenient offices. Our skilled dermatology experts will perform a skin patch test and other diagnostic interventions to provide an accurate diagnosis and offer the most effective treatment.
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