Allergic Reactions

Denture Materials

Nickel—a constituent of cobalt chrome dentures. Sensitive patient may give a history of allergy to jewellery or watch castings.

Acrylic monomer (methylmethacrylate)—can cause an allergic reaction. Patients may complain of ‘burning mouth’. If a proven allergy consider the use of a cobalt chrome or stainless steel denture base.

Epimine—in polyether impression material. 

 

Local Anaesthetic Agents

True allergy is unlikely if no skin rash or tissue oedema.  More common for symptoms to be due to inadvertent intravascular injection (transient tachycardia produced) or patient anxiety (precipitating a faint.)  Direct challenge rather than patch testing should be performed, only in hospital setting.

 

Oro-Facial Granulomatosis (OFG)

Uncommon.  Clinical signs of OFG include: facial or lip swelling, gingivitis, oral ulceration of apthous type, mucosal tags, cobblestoned oral mucosa.

Can be associated with food allergies, such as benzoates (E210-219), tartrazine and cinnamonaldehyde.

Some develop Crohn’s disease (6%) or sarcoidosis later

 

Biopsy (deep down to muscle to not miss characteristic non-caseating granulomas) is confirmatory.  GI investigations to be considered.

 

 

 

 

 

 

 

Acquired Angio-odema

Severe type I allergic response affecting lips, neck and floor of mouth. Rapid onset. Usually an identifiable cause. (e.g. NSAID’s, latex rubber, antibiotics, certain food types)

Treatment of mild angio-odema—anti-histamines. Severe—treat as anaphylaxis

 

Hereditary Angio-oedema

Rare autosomal dominant genetic condition. Defect of C1-esterase inhibitor which leads to unimpeded complement response. Lips, neck, floor of mouth swelling, and swelling of feet and buttocks. Precipitated by trauma (minor) and stress. Treat acute attacks with fresh frozen plasma (as contains C1-esterase inhibitor. Treated prophylactically with Stanozol or fresh frozen plasma (contains C1 esterase inhibitor.) 

 

Lichenoid reactions

These can be clinically indistinguishable for the white patches of oral lichen planus. Several drugs, including gold, NSAID’s, antimalarials, hypoglycaemics and the antihypertensive agent methyldopa can cause clinical and histological reactions identical to lichen planus.  Also from contact with amalgam restorations-proven by positive patch testing The mechanism of such reactions is unknown.

 

Aphthae

Many patients with recurrent aphthous stomatitis are patch-test positive for certain foods and food additives.

Foods- cheese, chocolate, citrus fruits, tomatoes, nuts, marmite/bovril, red wine, bananas

Food additives-benzoates and cinnamon aldehyde (often found in processed foods and carbonated drinks.)

 

 

 

 

 

 

 

Erythema Multiforme

Immune complex disorder. May present as stomatitis, cheilitis and skin lesions. Can be a response to herpes virus, mycoplasma, HIV, drugs (sulphonamides, anti-convulsants, carbamazepine, tetracycline, penicillin, salicylates and barbiturates), food or environmental allergy.

Most so-called allergic reactions of the mouth are due to direct irritation by the substance.  Most reactions are mild, even if the patient is sensitized to the material. Several oral diseases exist in which there is an allergic component.