Allergies are diseases in which the body reacts to substances that are not actually harmful. Here, in particular, Type 1 and Type 4 allergies are emphasized as they are also for dermatologists and so skin doctors, of great importance. These allergies are referred to as the immediate-type and delayed-type respectively. The immediate type allergies lead to hay fever, can cause hives (urticarial) and can be responsible for atopic dermatitis (eczema). Contrarily, delayed-type allergies (contact allergies) cause eczema and skin irritations, especially on the hands.

Type 1
is a histamine-mediated allergy (not to be confused with histamine intolerance). Here, after contact with particular allergens such as flowers and tree pollen, cat and dog dander, molds and domestic mites, certain immune cells of the body release histamine in the bloodstream. This then acts as a mediator and causes a reaction in mucous membranes resulting in familiar symptoms such as a runny nose and teary eyes. Exposure to these allergens can also result in skin irritations such as hives or, if you are prone to atopic dermatitis, the condition of the affected area can worsen.
In food allergies, this histamine is released after intake of the allergen in the digestive tract and it can cause symptoms such as malaise, nausea, vomiting, constipation, bloating and diarrhea.

Type 4 allergies,
so-called contact allergies, result in a defense reaction of the skin after coming in direct contact with the allergen (e.g., metals, dental fillings, cosmetics, fragrances, etc.). The result of this is eczema, usually on the hands or on the body parts which were exposed to the allergen; the belly from jeans snaps, earlobes after wearing nickel-rich jewelry and so on.

The dermatologist can find out through specific tests, such as the prick test or the patch test exactly which substances trigger allergic reactions in the patient. In addition, the patient’s blood can be examined for allergens.

Today, dermatologist treat dermatitis without cortisone, if possible. The known triggers should be avoided and it is recommended to use an antihistamine to reduce the frequent itching and to block the released histamine.

In the case of hay fever, the allergist or dermatologist should consider the possibility of allergy vaccination (desensitization, hyposensitizing). This allows the patient to cure the allergy.

Are you looking for help by allergies?