Contact dermatitis: clinics and pathology

Contact dermatitis or eczema is a polymorphic inflammation of the skin. It occurs at the site of contact with irritating or antigenic substances. In the acute phase there is occurrence of itching erythema, papules, and vesicles, whereas in the chronic phase there is dryness, hyperkeratosis, and sometimes fissures. Contact dermatitis can be divided into irritant and allergic types. Allergic contact dermatitis is a type-IV T-cellmediated reaction occurring in a sensitized individual after contact with the antigen/allergen. Such antigens are usually low molecular weight substances (MW ~500), called haptens; 3000 contact allergens are known. The diagnosis of contact allergy is made on the basis of the history, clinical findings, and a positive epicutaneous test result. Allergic, but not irritative, contact dermatitis can spread beyond the area of contact to other body parts. Eczematous lesions are characterized by a mononuclear infiltrate consisting mainly of T cells in the dermis and epidermis, together with an intercellular epidermal edema—that is, spongiosis. In allergic contact dermatitis, skin-applied antigen is taken up by epidermal Langerhans cells and transported with the afferent lymph to the regional lymph nodes. Here, naive T lymphocytes are sensitized to become antigen-specific effector T cells, which then leave the lymph node, enter the circulation, and are recruited to the skin by means of specific cell surface molecules, to form the infiltrates. Cytokines released by infiltrating T cells eventually cause keratinocyte apoptosis.     

Allergic contact dermatitis associated with the use of facemask on a patient with a history of atopy

Allergic contact dermatitis (ACD) is a skin inflammation caused by an allergic reaction after contact with small external substances capable of being absorbed by the skin. There are several studies describing allergic reactions to intraoral orthodontic appliances, especially those containing nickel. Allergic reactions due to extraoral appliances are not as frequent, and there are relatively few studies about them. Extraoral eactions are attributed to metallic, elastic, or textile parts of the extraoral appliances. This article's purpose was to report the appearance of an allergic contact dermatitis reaction in a 9-year, 2-month-old female patient, with a history of atopic dermatitis, after an orthodontic facemask was fitted. Rapid maxillary expansion was also performed with a Hyrax appliance while a facemask was used. Early diagnosis of this pathology is essential in order to achieve a total regression of the reaction. Orthodontists should be aware that ACD can be caused by facemasks in predisposed patients.     

Skin problems associated with routine wearing of protective gloves in dental practice

Guidelines on cross-infection control recommend the wearing of operating gloves by dental practitioners whilst carrying out routine examinations and treatment on all patients. However, there are a number of dermatological problems that may be associated with the routine wearing of protective gloves in dental practice. This paper describes the aetiology and clinical features of three types of contact dermatitis, ie irritant contact dermatitis, allergic contact dermatitis and contact urticaria. The management of these skin conditions is discussed. Advice is given concerning routine handcare for all dental practitioners.     

Allergic contact stomatitis from a gold alloy--fixed partial denture

Allergic contact stomatitis to gold is rare. To our knowledge, seven cases caused by dental restorations have been previously reported. Each of the patients was female. This report documents an allergic reaction to gold in a fixed prosthesis. A female patient, previously sensitized to gold earrings, experienced an itching and burning pain sensation and ulceration of the oral tissues adjacent to the gold restoration. Patch tests confirmed the allergy to gold. The dentist needs to be aware of the symptoms that are characteristic of the allergic manifestations of gold. Inquiries about allergies to metals and jewelry should be a part of the medical history. Any patient experiencing pain, itching, burning, and ulceration of the mucosa adjacent to a cast gold restoration should be suspected of an allergic contact stomatitis.     

Contact allergy in and around the mouth

Contact allergic reactions in and around the mouth are not frequent, but they can have very unpleasant consequences. Discussed are the most important materials that can cause reactions in patients and dental personnel. Particulary the enormous increase in the use of latex gloves has caused a rise in latex allergy and contact dermatitis by rubber additives. Acrylates are also important contact sensitizers; they can cause the dentist serious trouble.     

Cross-reactions of multifunctional methacrylates and acrylates.

Dental acrylic monomers (that is, acrylates and methacrylates) are important occupational sensitizers. Acrylic monomers may also cause allergic reactions in dental care. Unfortunately, acrylic monomers cross-react--that is, allergic sensitization induced by one acrylic compound extends to one or more other acrylic compounds. Therefore, sensitized individuals are often multiallergic and, accordingly, cannot be exposed to any of the compounds. In the present review aspects of cross-reactivity in general and data from animal studies of cross-reactivity of multifunctional methacrylates and acrylates are summarized. A multitude of acrylic monomers is used in dentistry, and when patients or dental personnel become sensitized, it is of great importance to identify the dental acrylic preparations to which the sensitized individual can be exposed. Sensitized dental workers are known to have ceased working in dentistry owing to occupational allergic contact dermatitis or asthma, caused by dental acrylic monomers. Unfortunately, cross-reactivity of acrylic monomers used in dentistry is not sufficiently mapped to enable selection of an appropriate compound for the sensitized person. Another important aspect is that product declarations of dental acrylic materials should show all acrylic compounds present in the products--even acrylic monomers/impurities with lower concentrations than 1%. This could help to select a product that the sensitized individual could use.     

Allergic reactions to local anesthetics

In this article type I and type IV allergic reactions evoked by local anaesthetics are discussed. Contact dermatitis (type IV) reactions are mainly caused by local anaesthetics of the ester-type like procaine. Both contact dermatitis and anaphylactic reactions (type I) can be caused by anaesthetics of the amide-type (e.g. lidocaine), but these reactions are rare. Intra- and epicutaneous tests can be useful to prove allergy, but sometimes provocation tests are necessary. Many reactions are not caused by an allergic mechanism.     

Heat shock proteins in the pathogenesis of inflammatory skin diseases

Heat shock proteins (HSPs) are highly conserved molecules and distributed widely in nature. They are also distributed in the skin, however, only limited information is available on the role of HSPs in the skin diseases. Immunohistochemical study of HSPs in the skin revealed that HSPs are differently expressed in the epidermal cells of patients with systemic lupus erythematosus (SLE), atopic dermatitis, graft versus host disease (GVHD) and so on. In normal healthy skin HSPs are constantly expressed in the epidermal cells. HSPs are expressed in the skin according to the influence of both external and internal milieu of the diseased conditions. Cytokines released in the skin strongly affect to express HSPs in epidermal cells. HSPs expressed in the skin can be targets for infiltrated T cells to modulate immune response of skin diseases. Roles of HSPs in the pathogenesis of SLE, GVHD, atopic dermatitis and psoriasis are discussed in this review. HSPs play an important role in the pathogenesis of many inflammatory skin diseases. They can be the molecules to evaluate both diseased conditions and inflammatory process of the skin diseases.     

Systemically induced contact dermatitis from dental rosin

Rosin is a ubiquitous contact sensitizer which may be present in dental materials such as periodontal dressings, impression materials, cements, and cavity varnishes. When a hypersensitive person is exposed to a sensitizer, allergic contact dermatitis/stomatitis may develop, most commonly after direct skin/mucosa contact with the sensitizer. However, widespread dermatitis may develop after systemic administration of the sensitizer, and this paper reports the case of a rosin-hypersensitive man who developed widespread eczematous dermatitis after dental treatment with a rosin-containing product.     

Cross-reactions of multifunctional methacrylates and acrylates

Dental acrylic monomers (that is, acrylates and methacrylates) are important occupational sensitizers. Acrylic monomers may also cause allergic reactions in dental care. Unfortunately, acrylic monomers cross-react—that is, allergic sensitization induced by one acrylic compound extends to one or more other acrylic compounds. Therefore, sensitized individuals are often multiallergic and, accordingly, cannot be exposed to any of the compounds. In the present review aspects of cross-reactivity in general and data from animal studies of cross-reactivity of multifunctional methacrylates and acrylates are summarized. A multitude of acrylic monomers is used in dentistry, and when patients or dental personnel become sensitized, it is of great importance to identify the dental acrylic preparations to which the sensitized individual can be exposed. Sensitized dental workers are known to have ceased working in dentistry owing to occupational allergic contact dermatitis or asthma, caused by dental acrylic monomers. Unfortunately, cross-reactivity of acrylic monomers used in dentistry is not sufficiently mapped to enable selection of an appropriate compound for the sensitized person. Another important aspect is that product declarations of dental acrylic materials should show all acrylic compounds present in the products—even acrylic monomers/impurities with lower concentrations than 1%. This could help to select a product that the sensitized individual could use.     

Bonding efficacy and side effects of the high purity glyceryl mono-methacrylate

The purpose of this study was to examine the efficacy of experimentally developed high purity glyceryl mono-methacrylate (GM) as a dentine primer and to evaluate the possibility of allergic reaction. The efficacy of experimental dentine primers was evaluated by measuring the polymerization contraction gap width and the tensile bond strength. Allergic reaction was evaluated by the guinea-pig maximization test. The skin reaction was evaluated according to the criteria of the International Contact Dermatitis Research Group. Contraction gap formation was completely prevented and the tensile bond strength was not significantly affected by priming with GM on high-purity GM. The allergic response decreased when high-purity GM was employed as the challenger. It was concluded that the clinical use of the high-purity GM is beneficial as the delayed allergic reaction could be avoided with no detrimental effect on the dentine bonding.     

Propolis allergy: a cause of oral mucositis with ulceration

Propolis has been used since ancient times in folk medicine for its alleged beneficial effects. It is a potent sensitizer and is well recognized as a cause of occupational allergic eczematous contact dermatitis in apiarists. Recently, there has been an increase in allergic eczematous contact dermatitis because of nonoccupational exposure to propolis in "natural products" and biocosmetics. This report describes a patient who had acute oral mucositis with ulceration as a result of using propolis-containing lozenges.     

Occupation-related allergies in dentistry

BACKGROUND: Allergies to natural rubber latex (NRL) were unknown in dentistry until 1987. That changed with the publication of a report documenting NRL-based anaphylaxis in a dental worker. This case and others prompted regulatory and manufacturing changes in rubber products and increased awareness throughout the profession. However, other common dental chemicals cause allergic reactions and irritation and often are handled with insufficient precautions. Although recognition of NRL allergy has improved, awareness of other potential allergens and irritants in dentistry still is limited. OVERVIEW: Recent research indicates that the prevalence of NRL protein allergy may be decreasing. In contrast, occupation-related dermatoses associated with other dental products may be more common. Encounters with bonding agents, disinfectants, rubber, metals and detergents can cause occupation-based irritant contact dermatitis and allergic contact dermatitis. These conditions may be found in more than one-quarter of dental and medical personnel. Therefore, dental-specific information about the recognition and management of allergic and irritant reactions is needed. CONCLUSIONS AND CLINICAL IMPLICATIONS: The prevalence of occupation-related dermatitis may be increasing in dentistry. Reducing exposure to potential irritants and allergens and educating personnel about proper skin care are essential to reversing this trend.     

Specific antibody in gingiva and submandibular nodes of monkeys with allergic periodontal disease

Gingiva and submandibular lymph nodes from 12 squirrel monkeys that had been sensitized to ovalbumin, and from 4 unsensitized monkeys, were studied for the presence of cells containing specific antibody after intracrevicular challenge with ovalbumin-soaked thread. Immunofluorescent methods were used to identify antibody to ovalbumin in cells in these tissues.
The chronic allergic response in the gingiva of sensitized animals that had been challenged three times per week for three months did include cells containing antibody to the antigen used for sensitization and challenge. Such cells were not found in gingiva from similarly treated unsensitized monkeys, or from sensitized monkeys challenged for a shorter time.
A few antibody-containing cells were found in the submandibular lymph nodes ipsilateral to chronic intracrevicular placement of antigen in unsensitized animals, indicating active sensitization by gingival absorption of antigen. Antibody formation by cells in submandibular nodes, induced by systemic sensitization, was continued in nodes ipsilateral to gingival challenge, but tended to disappear in contralateral nodes.     

Atypical pattern of (meth)acrylate allergic contact dermatitis in dental professionals

(Meth)acrylates in dental bonding agents are a common source of allergic contact dermatitis in dental professionals. The distribution of the contact dermatitis is commonly on finger tips, but is determined by individual habits as demonstrated by the two case reports in this article. Despite the site of contact dermatitis, the bonding agents are often not suspected as a source of contact allergy due to misconception regarding the protective effect of natural rubber latex gloves. With these case reports, we endeavour to emphasize the inadequacy of the latex gloves in protecting against the (meth)acrylate induced contact allergy and also list the measures a dental professional needs to incorporate in order to minimise the risks of sensitisation to (meth)acrylates.     

Contact allergy to cinnamon: case report

Allergic contact stomatitis is a rare disorder that is unfamiliar to most clinicians. The vast majority of cases are associated with consumption of products containing cinnamaldehyde or cinnamon essential oil, which are used as flavourings because of their pleasant taste and sensation of freshness. We report here the case of a patient who was diagnosed with alllergic contact stomatitis due to cinnamon-flavoured chewing gum. The clinical features of allergic contact stomatitis, which may occur indiscriminately on any of the oral mucosa, include edema and erythroplakic, ulcerous or hyperkeratotic changes, generally accompanied by a burning sensation. The histopathologic aspect of allergic contact stomatitis is nonspecific but tends to support the clinical diagnosis. Treatment generally consists of eliminating the causal agent. To avoid unnecessary diagnostic procedures and treatments, it is important for clinicians to recognize this disorder to be able to diagnose it quickly and accurately.     

Allergic contact stomatitis from colophony

Colophony is an ubiquitous contact sensitizer which may be present in dental materials, such as periodontal dressings, impression materials, cements, fix adhesives and varnishes. Exposure to a sensitizer in a hypersensitive person may initiate an allergic contact dermatitis/stomatitis.This usually occurs after direct skin/mucosa contact with the sensitizer. This paper reports the case of a colophony hypersensitive male who developed contact stomatitis after dental treatment with a colophony-containing product. CLINICAL RELEVANCE: Sensitizing colophony is present in Duraphat 2.26%F varnish, a fluoride varnish used all over the world. A case of hypersensitivity to Duraphat 2.26%F varnish is presented in a patient who, at the initial visit, indicated only an allergy to sticking plasters.     

Splenocyte cytokine profile in mouse with oral mucosa-sensitization and oral-tolerization by NiSO(4)

Metals used in the oral cavity have been reported to cause various allergic diseases of the skin and mucosa. Skin manifestations due to dental restorations appear not only in the oral cavity, but also on the hands, feet or the whole body, as in the cases of pustulosis palmoplantaris and lichen planus. These phenomena implicate different pathogeneses from that of conventional skin sensitization and tolerance. Therefore, we compared skin and oral mucosa sensitization with nickel and oral tolerance for nickel in a mouse model. Female C57BL/6J mice were sensitized by injection of NiSO(4) into the skin or oral mucosa. Allergic reactions were evaluated by the mouse ear swelling test and splenocyte proliferation and cytokine profiles. Skin and oral mucosa sensitization succeeded in all mice. Ear swelling was significantly greater in the skin- than in the oral mucosa-sensitized mice at 48 hr after challenge. Ear swelling was also suppressed by single oral administration of NiSO(4) in both the skin- and oral mucosa-sensitized mice to the level of that in nonsensitized mice. Splenocytes from skin-sensitized mice proliferated similarly to those from oral mucosa-sensitized mice. Splenocytes from orally-tolerized mice also showed similar proliferation activity to those from skin and oral mucosa-sensitized mice. In the challenge phase, IL-2, IFN-γ, and IL-10 production was induced in splenocytes from both skin- and oral mucosa-sensitized mice. However, IL-4 was induced only in those from skin-sensitized mice. In addition, IL-4 in splenocytes from oral mucosa-sensitized mice was up-regulated to the level in those from skin-sensitized mice by oral tolerance. These results suggest that sensitization sites in mice influence not only the degree of excitation, but also Th-1 and Th-2 balance in the challenge phase and oral tolerance.     

Latex glove allergy in dental practice

Skin reactions due to the use of latex examination gloves occur frequently in dental practice. They consist of immediate type I allergy to natural latex protein, type IV delayed hypersensitivity to rubber additives and irritant dermatitis. Type I allergy to latex protein can cause contact urticaria, angioedema, rhinoconjunctivitis and asthma in the dentist, the dental assistant and also in the patient. Exceptionally, latex allergy can cause a life-threatening anaphylactic reaction. Cross reactions to tropical fruit can occur in the latex allergic patient. Type IV allergy causes allergic contact dermatitis. Rubber additives are also present in synthetic rubber. Glove advice for latex allergic patients are presented.     

T lymphocytes, Langerhans cells and HLA-DR expression on keratinocytes in oral lesions associated with amalgam restorations

It has been shown recently that patients with mucosal lesions confined to areas opposing amalgam restorations (contact lesions) show a high rate of allergic reaction towards mercury. These lesions may, therefore, represent a contact hypersensitivity reaction. Contact lesions often have a lichenoid appearance. From a pathogenetic and differential diagnostic point of view we therefore evaluated the presence of lymphocyte subpopulations, Langerhans cells (LC) and the expression of HLA-DR antigens on mucosal keratinocytes in biopsies of contact lesions (Group 1) and in lichen planus lesions with (Group 2) and without (Group 3) partial contact with amalgam restorations. T lymphocytes dominated in all three groups and LC counts were similar. HLA-DR positive keratinocytes were found in 18-36% of lesions in all three groups. Thus, the immunologic parameters examined are not of value in discriminating between the types of lesions studied. Rather, it seems that the pattern observed is a common reaction of the oral mucosa to known (amalgam restorations) and unknown factors.