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  Atopic eczema, irritant dermatitis and contact dermatitis


Contact dermatitis is a skin disease that occurs in two forms namely irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD). While the former is caused due to contact with irritant agents, the latter is caused by exposure to allergens and unlike irritant contact dermatitis is an immunological reaction. Allergic contact dermatitis can also be defined as a late-onset hypersensitivity of the skin when it is exposed to substances to which a patient has a history of sensitivity. Allergic contact dermatitis constitutes 20% of all contact dermatitis cases, the rest taken up by irritant contact dermatitis.

This section of the website looks into the various aspects of allergic contact dermatitis with helpful tips on how to manage the condition under the following categories:

What is allergic contact dermatitis?

It begins with a summary of allergic contact dermatitis, with an outline of its basic differences with irritant contact dermatitis, symptoms, diagnosis, differential diagnosis, prevalence, a list of the major allergens and treatment.

Clinical presentation of contact dermatitis

It takes off from here with more details about the clinical manifestation of allergic contact dermatitis. Clinical appearance of the disease involves a study of its site of occurrence in the body (arms, neck, ears, etc.) vis-à-vis the offending substances, its size, its shape, its degree of inflammation and form of occurrence. Knowledge of the clinical features is important for a proper diagnosis of the disease.

Patch testing for contact allergens

Another major diagnostic tool for allergic contact dermatitis is patch testing. Hence, it has also been dedicated a separate article in this section of the portal. Patch testing is considered the ‘gold standard’ in the diagnostic approach to contact dermatitis. This clinical procedure involves identifying and differentiating allergens or irritants that trigger contact dermatitis.

The TRUE® Test method is an established patch testing and is approved by the US Food and Drug Administration (FDA). However, it tests for only 23 allergens. However, many patch test centers prefer to include more than 50 allergens in their procedures, following other extended panels like the North American Contact Dermatitis Group Screening Series and the European Standard Series. Whatever the method, it is very important to know about the preparatory steps to patch testing, about the process and how to go about it in details, such as knowing the various allergens, how to prepare the patient and the products for the test, the correct application of the patches and how to read and interpret the patches.

Occupational contact dermatitis

One very vital aspect of allergic contact dermatitis is its workplace related occurrence. This also requires a detailed discussion, which has been incorporated in this website. The details include the various occupations where one is more prone to contact with offending substances, either in the form of irritants or allergens. Take for instance the job of a farmer where he is heavily exposed to irritants like milker’s eczema (detergents), tractor lubricants and fuels and allergens like malathion, pyrethrium insecticides, fungicides, rubber, ragweed and marsh elder. The article on this topic outlines many such other occupations and their related allergens.

Top ten contact allergens

Apart from the workplace related allergens, it is also necessary to know and be able to identify the various allergens in our surroundings that we may be susceptible to. The North American Contact Dermatitis Group (NACDG) recognizes ten major contact allergens. They are the three metals nickel (nickel sulfate), gold (sodium gold thiosulfate), cobalt (cobalt chloride); 3 preservatives of formaldehyde, quaternium-15 and thimerosal; 2 topical antibiotics neomycin sulphate and bacitracin 13; and 2 fragrance elements of fragrance mix and balsam of peru (myroxylon pereirae).

Cosmetics dermatitis

Among the various allergens, ingredients of cosmetic products are major offenders. Cosmetic allergy has been on the rise with its increasing use especially among adolescents and young adults. Moreover, there is a widespread lack of awareness about the safe use of these products and the necessity to be educated about reading labels for product ingredient information.

Balsam of peru allergy and avoidance diet, rubber latex allergy, shoe allergy and herbal extract allergies

Balsam of peru allergy is also a very common occurrence among fragrance allergies. The North American Contact Dermatitis Group (Nallergic contact dermatitisG) classifies fragrances as the fourth most common allergen and the most common cosmetic ingredient to cause allergic contact dermatitis (allergic contact dermatitis). For individuals who are allergic to certain food substances it is vital to follow an avoidance diet.

This section of the website also includes facts about three other common types of allergic contact dermatitis’s namely rubber latex allergy, shoe allergy and herbal extract allergy.

Allergic contact dermatitis in children

Allergic contact dermatitis in children has been on the rise and closely associated with lifestyle changes like the increasing use of offending agents like jewelry, body paints, cosmetics etc. In the last 10-20 years, contact allergy has become a challenge for pediatricians worldwide. Positive patch test results have registered a highly variant rate of 14.5% to 70% of cases, with clinically relevance at 20% to 92% of them.

Allergic contact dermatitis treatment

The first line of approach in allergic contact dermatitis therapy is a strict avoidance of the allergens. This apart, symptomatic therapy also becomes necessary in certain cases. Generally, the major treatment options for allergic contact dermatitis include corticosteroids and phototherapy. When allergic contact dermatitis cannot be managed by these two options secondary and latest means such as anti-inflammatory agents and immunomodulators are increasingly being used. Know the fine points in the relevant article under allergic contact dermatitis.