Frequencies

The risk of developing a skin rash due to allergy once in a lifetime is estimated at about 15% in Central Europe. The most frequently affected body parts are hands, genital and anal area and the face.

Symptoms

The skin rash caused by an allergy usually runs in different phases. In the beginning, there is only a light red discoloration of the affected area. As the rash progresses, the tissue becomes swollen due to water retention (edema).

This usually happens within the first 6 hours. Itching, burning and pain can occur during this time. Within the first 12-24 hours, the accumulated water in the skin layers causes the skin cell structure to tear, resulting in weeping blisters.

After about 3 days, the reaction begins to recede. First crusts and scales are formed from the burst blisters, until healing occurs. If the reaction does not remain a one-time reaction, but rather results in repeated contact with the substance causing the allergy, chronic allergic contact eczema develops.

This often occurs during occupational stress where it is difficult to avoid the triggering substance. During prolonged exposure, the swelling and blister formation is much less pronounced. In this case, the focus is on increasing keratinization and coarsening of the skin, which subsequently leads to a very cracked skin appearance.

Cortisone is the main active substance used to counteract the skin reaction. This is applied to the affected areas and curbs the excessive immune reaction of the body. It is important here to ensure that the carrier substance is suitable for the respective symptoms.

For example, a watery preparation should usually be applied to a weeping rash, and a greasy preparation to a dry rash. Antihistamines can be used to eliminate the allergic trigger mechanisms and above all to relieve itching. These can be used locally as an ointment or systemically as tablets.

UV light therapy, which also inhibits the immune reaction, can also help. In the case of inflammation of the skin, there is always the risk that bacteria will penetrate the skin barrier and lead to an additional bacterial infection. To prevent this, disinfectants can be used. In the case of rare severe courses, there is still the possibility of resorting to calcineurin inhibitors (e.g. tacrolimus).