Contact dermatitis (CD) is a relatively frequent entity in clinical practice. It is a type of dermatitis whose prevalence has increased in recent years and currently affects approximately 15-20% of the population. The study by means of epicutaneous tests is fundamental in the diagnosis of contact sensitization.
In any case, it is an inflammatory skin disease induced by exposure to an irritant or an external allergen that would provoke an immunological reaction. Contact dermatitis can be irritant (ICD) or allergic (ACD).
Irritant contact dermatitis (ICD)
ICD is the most common (80%) and the most frequent in children. Direct contact with an irritant substance on the skin produces an inflammatory reaction. Even so, it can affect anyone and symptoms appear after repeated contact and with low potent irritants.
In this regard, soaps, detergents, acids, bases, solvents, saliva, urine and fecal matter are the most common triggers of ICD.
Allergic contact dermatitis (ACD)
ACD is seen in genetically predisposed and previously sensitized individuals, who react even with low concentrations of the allergen. Sensitization requires a prolonged contact time, usually months or years. However, it can sometimes appear within a few days. Some antigens require, for their activation, the energy captured from ultraviolet light.
The substances usually implicated in this type of contact dermatitis are the following: cosmetics and hygiene products containing perfumes and preservatives, drugs (neomycin, penicillin, sulfonamides and local anesthetics), clothing dyes, hair dyes and permanents, foods, rubber, plants, nail polishes (especially permanent ones), metals (nickel, chromium, mercury, cobalt) and the components of rubber products (latex, gloves and footwear).
In geriatric patients, the most prevalent allergy is to topical medications, cosmetics (more in women than in men), metals, rubbers and, to a lesser extent, to plastics and food.
How to treat this type of dermatitis
The basis of a correct treatment consists of avoiding contact with this type of substances, but in case it is not possible, the most important thing is to establish the adequate protection for each case.