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
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
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).
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.