A
contact allergy in the mouth or contact stomatitis is a hypersensitivity
mechanism of the cellular or delayed type and is, like contact dermatitis on
the skin, the result of a sensitization to a substance with which one has
previously come in contact, the "contact allergen".
The
oral mucous membrane, however, is less often affected by contact allergy than
the skin. A number of factors play a
role in this, such as the brevity of the contact with potential allergens,
which are also buffered and diluted by saliva, and the dense vascularization
whereby the substances are more rapidly resorbed into the bloodstream, whereby,
in contrast to skin contact, preferential tolerance is induced.
Diagnosis
of a contact allergy in the oral mucous membrane is difficult. This is not only because the testing method
for identifying the contact allergens responsible for the contact stomatitis is
unsatisfactory (possible false-negative results of patch tests on the skin),
but also because a contact stomatitis is often asymptomatic. In contrast to the clear clinical lesions on
the skin for a contact eczema (itching, redness, papules, vesicles, scaling,
etc.), a contact stomatitis produces primarily subjective symptoms: loss of the
sense of taste, numbness, burning sensations, and pain (rarely itching), and
sometimes even complaints of generalized itching, dizziness, headache,
gastro-intestinal problems, and malaise.
Rarely are there objective clinical phenomena such as redness, swelling,
vesicles, erosions, or ulceration. When
these phenomena are paired with cheilitis, perleche, or perioral dermatitis,
the diagnosis is, of course, facilitated.
Important
differential diagnoses around the mouth are irritation reactions and
intolerance reactions (for example, to food) in atopic patients.
A
contact allergy in the mouth can have several causes: local contact with dental
products (for example, local anaesthetics, antiseptics, dental-mould material,
dentures, dental fillings, and toothpaste), mouthwashes, lozenges, etc. Contact with oral medication, inhalants,
food (for example, conservatives, seasoning, and flavorings), and beverages.
Key words: stomatitis - mouth - dental of dentistry -
clinical symptoms