Allergic contact dermatitis: from causes to treatments.

Allergic contact dermatitis (ACD) is a skin inflammation or irritation caused by your skin getting in contact with substances that trigger an immune response. Let’s take a quick look at its causes, symptoms, diagnosis, affected areas and possible treatments.

black and white feet


What are the typical allergens in ACD? 

Allergic contact dermatitis is caused by contact with substances called allergens. The list of possible allergens is virtually endless. These can be metals, such as chromium or nickel, as well as plants, flowers, perfumes, essences, dyes, preservatives, resins, and so on. Once the substance comes into contact with an allergic person’s skin, an inflammation is triggered and the skin becomes red and itchy. Allergens are also present in environments and products that may seem harmless, such as nickel (which is also contained in cosmetics) or the chromium salts found in many shoes. 


Skin rashes and frequent discomfort.  

Red patches, vesicles, scabs, erythema, severe oedema with blisters, ulceration: skin inflammation from allergic contact dermatitis can take different  forms. Initially, intense itching is the most prominent discomfort, while pain is usually due to scratching or infection. ACD can become chronic over time: when this happens, your skin in the affected area becomes thicker, darker in colour and covered in scales. 


How the patch test works.    

Allergic contact dermatitis can be diagnosed by studying a patient’s skin alterations and habits or through a patch test. How does the test work? Special patches containing a range of allergenic substances are applied to the patient’s upper back. The skin is then examined at a minimum of 48 hours after application to see whether the patient tests positive. Reading the results is not easy, so a specialist is always required. 


What are the most sensitive areas of the body?

Allergic contact dermatitis (ACD) can occur on many different parts of your body: your face or ears, your neck or armpits, your hands and feet. Much depends on the type of allergen you are sensitive to. For instance, if you are allergic to nickel in soaps, rash is likely to appear on your face and hands. If you are allergic to chromium salts, you may develop ACD on your feet whenever wearing shoes containing this allergen. 


How to treat allergic contact dermatitis.Unfortunately, there is no known cure for ACD to date. Treatments prescribed by specialists can only keep the irritation and itching under control. These include cold compresses, topical corticosteroids and systemic antihistamines. But the only way to prevent inflammation is prevention, that is avoiding exposure to the causative agent. Sometimes this can be very difficult, as is the case with construction workers who need to avoid chromium in concrete. In other circumstances it may be easier, as it’s just a matter of either identifying a detergent causing the irritation or avoiding certain clothing or wearing