Occupational contact urticaria from diglycidyl ether of bisphenol A epoxy resin

BACKGROUND: Epoxy resin (ER) is a common cause of occupational allergic contact dermatitis (ACD), but contact urticaria from ER is very rare. METHODS AND RESULTS: A plastic-product worker first developed ACD from diglycidyl ether of bisphenol A (DGEBA) epoxy resin, and subsequent exposure resulted half a year later in contact urticaria: first with edema of the lips and eyelids, and later an urticarial reaction on the upper chest, with strong swelling of the eyelids and tightness of the throat. The diagnosis was based on a positive skin prick test to his "own" ER compound, a positive prick test reaction to DGEBA, and a positive skin provocation test with the ER compound and DGEBA. The contact urticaria test reaction was strongly aggravated when the allergen was wiped off with an alcohol solution, apparently because the solution enhanced the penetration of the allergen. CONCLUSIONS: Our case is of interest, first, because contact urticaria from ER is very rare, and second, because this is the second report in which a strongly intensified contact urticaria reaction was provoked by an alcohol solution. We suggest that if the contact urticaria provocation test with low-molecular-weight chemicals is negative, a contact urticaria provocation test with alcohol (CUPTA) should be performed.     

The allergy and immunology specialist

The practice of medicine transcends our neat borders of demarcation between the myriad of medical specialties and medical disciplines. There are no two specialties in which this clinical interface is more blurred than the clinical interface between allergy and dermatology. With a background in both dermatology and allergy, I address where the specialty of allergy/immunology is heading, as we navigate the coastal waters separating my two primary disciplines. I also discuss the tools traditionally used only in dermatology, which are now being used increasing by a vanguard of allergists to aid in the diagnosis and treatment of allergic skin disease.     

T-cell subpopulations in the development of atopic and contact allergy

Remarkable progress has been made in our understanding of the pathogenesis of skin diseases mediated by T cells. T-cell subsets responsible for the expression and regulation of allergic contact dermatitis to small chemicals or 'haptens' have been defined further, and the dynamics of T cells involved in the pathogenesis of atopic dermatitis have been clarified. In addition, studies are beginning to reveal the important contribution of skin resident cells to atopic dermatitis and the underlying molecular mechanisms.     

Contact allergy to budesonide contained in a nasal spray

We describe a case of contact allergic sensitization to budesonide in a nasal spray used in the treatment of allergic rhinitis. No cross-sensitivity to other topical corticosteroids was found.     

Nickel, cobalt, chromium, palladium and gold induce a mixed Th1- and Th2-type cytokine response in vitro in subjects with contact allergy to the respective metals

Nickel (Ni), the main cause of contact allergy to metals, induces in vitro production of both Th1- and Th2-type cytokines in peripheral blood mononuclear cells (PBMC) from allergic subjects. Because the knowledge of the cellular immune response to other metals involved in contact allergy has been limited, we investigated the cytokine profile induced by Ni, cobalt (Co), chromium (Cr), palladium (Pd) and gold (Au) in PBMC from patients with patch test reactivity to the respective metals. PBMC from patients with patch test reactivity to Ni, Co, Cr, Au and/or Pd (n = 31) and non-allergic controls (n = 5) were stimulated in vitro with corresponding metal salts. Th1- [interleukin (IL)-2 and interferon (IFN)-gamma] and Th2- (IL-4 and IL-13) type cytokine responses were measured by enzyme-linked immunospot (ELISpot) and/or enzyme-linked immunosorbent assay (ELISA). All metals induced a mixed Th1- and Th2-type cytokine production in PBMC from individual patients with patch test reactivity to the corresponding metal, but not in control PBMC. Significantly higher responses in the patient versus controls were found for Cr (IL-2 and IL-13), Pd (IL-2 and IL-4), Au (IL-13 and IFN-gamma) (all P < 0.05) and Ni (all four cytokines; P < 0.01) but not Co. Overall, 71% (37/52) and 89% (81/91) of the positive and negative patch test reactivities to metals, respectively, were matched by the in vitro reactivity. In conclusion, our data suggest that sensitization to Co, Cr, Pd and Au results in a cellular immune response of a character similar to the mixed Th1- and Th2-type cytokine profile shown previously to be induced by Ni.     

Atopic dermatitis and allergic reactions to individual fragrance chemicals

Background:  Allergic contact dermatitis prevalence is reported as equal in atopic and nonatopic dermatitis. Atopic dermatitis is under‐represented in those with allergic contact dermatitis to agents having cutaneous and dietary exposure. We compared rates of atopic dermatitis between patients with allergic contact dermatitis arising out of individual fragrance chemicals with known oral/cutaneous exposure against exclusively cutaneous exposure. Methods:  Between 1982 and 2007, 37 065 dermatitis patients were tested with Fragrance mix I. Those who were positive were tested for individual fragrance allergy. Chemicals were categorized according to whether their exposure pattern was solely cutaneous, oral or mixed. Current and past atopic dermatitis rates were compared between the whole population and groups allergic to individual fragrances. Age and gender were controlled. Results:  Cinnamic alcohol and cinnamal allergy groups had reduced rates of both ‘current’ [24/266 (9.0%) P = 0.0008, 38/364 (10.4%) P = 0.0005] and ‘past’ atopic dermatitis [44/266 (16.5%) P = 0.009, 70/346 (19.2%) P = 0.037]. Atopic dermatitis rates in groups allergic to Evernia prunastri and hydroxycitronellal (cutaneous exposure only) were not reduced [120/597 (20.1%) and 41/153 (26.8%)]. Groups allergic to cinnamic alcohol (P < 0.0001, P < 0.0001) and cinnamal (P < 0.0001, P < 0.004) had reductions in ‘current’ and ‘past’ atopic dermatitis, compared with Evernia prunastri. Conclusions:  Patients allergic to individual fragrances with dietary exposure have reduced rates of atopic dermatitis. This suggests that patients with atopic dermatitis have heightened oral tolerance to dietary haptens, in contrast to the known close association of atopic dermatitis with food‐protein allergy. Haptens may interfere with food protein tolerance by binding to soluble protein to alter its configuration and immunogenic profile.     

Fabrication of UV epoxy resin masters for the replication of PDMS-based microchips

This paper presents two methods for the fabrication of UV epoxy resin masters for the replication of PDMS-based microfluidic chips. In the first method, the epoxy resin master is fabricated from a negative glass template manufactured using conventional lithography and wet etching techniques. However, in the second method, the master is produced simply by exposing a layer of UV epoxy resin coated on a glass substrate. Although the first method enables the replication of multiple PDMS structures from a single master, the latter method avoids the requirement for a wet chemical etching process and enables the epoxy master to be produced in 40 min or less. The experimental results show that the epoxy resin masters enable the mass production of PDMS replicas with highly precise geometrical tolerances. A series of electrokinetic focusing experiments are performed using PDMS microchips replicated from the current epoxy resin masters. The experimental results obtained for the width of the electrokinetically-focused sample stream under different focusing ratios are found to be in good agreement with the theoretical predictions. The sample handling characteristics of the microfluidic chips are also investigated. It is shown that the sample flow can be electrokinetically pre-focused into a narrow stream and then guided to the desired outlet port by applying a simple voltage control model. Finally, it is demonstrated that through an appropriate alignment of the sample flow and the conductivity gradient, the electrokinetic instability phenomenon can be induced at a relatively low electrical field strength of 0.35 kV/cm.     

Allergic contact gingivostomatitis from a temporary crown made of methacrylates and epoxy diacrylates

Occupational allergic contact dermatitis caused by (meth)acrylates is common in dental personnel, whereas dental acrylic fillings and crowns have rarely been reported to cause problems in dental patients. Here we report on a 48-year-old woman who developed gingivitis, stomatitis, and perioral dermatitis after a temporary crown made of restorative, two-component material had been inserted. The manufacturer stated that the temporary crown base paste and catalyst contained three (meth)acrylates, namely, a proacrylate, which is a modification of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (BIS-GMA); a tricyclate, which is a saturated, aliphatic, tricyclic methacrylate; and urethane methacrylate. The manufacturer refused to give more exact information on the (meth)acrylates. Patch testing revealed that the patient was highly allergic to BIS-GMA, other epoxy diacrylates, and (meth)acrylates, as well as to the base paste and catalyst of the temporary crown. Accordingly, it was concluded that the allergic reaction was caused by BIS-GMA, or a cross-reacting (meth)acrylate, or other (meth)acrylates in the temporary crown.     

Diagnostic approach in allergic and irritant contact dermatitis

Contact dermatitis is a highly frequent disease with a significant impact on the quality of life of the affected patients and a relevant socioeconomic impact. According to the pathophysiological mechanisms involved, two major types of contact dermatitis may be recognized: irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD). The two types may, and often do, coexist. Differentiating between ICD and ACD is often difficult in the clinical setting. The basis for a diagnosis of either ICD or ACD is mainly established by a comprehensive clinical history and physical examination, as well as by performing appropriate diagnostic patch testing. The only useful and reliable method for the diagnosis of ACD remains the patch test. Positive patch test results, the current and/or past relevance of which has to be assessed, are confirmative of contact sensitization. Additional tests, such as the repeated open application test or the provocative use test, are sometimes necessary to confirm a causal relationship. This algorithmic diagnostic approach will allow the adoption of rational measures of allergen or irritant avoidance and the implementation of realistic patient information and education.     

Mast cells and basophils in cutaneous immune responses

Mast cells and basophils share some functions in common and are generally associated with T helper 2 (Th2) immune responses, but taking basophils as surrogate cells for mast cell research or vice versa for several decades is problematic. Thus far, their in vitro functions have been well studied, but their in vivo functions remained poorly understood. New research tools for their functional analysis in vivo have revealed previously unrecognized roles for mast cells and basophils in several skin disorders. Newly developed mast cell‐deficient mice provided evidence that mast cells initiate contact hypersensitivity via activating dendritic cells. In addition, studies using basophil‐deficient mice have revealed that basophils were responsible for cutaneous Th2 skewing to haptens and peptide antigens but not to protein antigens. Moreover, human basophils infiltrate different skin lesions and have been implicated in the pathogenesis of skin diseases ranging from atopic dermatitis to autoimmune diseases. In this review, we will discuss the recent advances related to mast cells and basophils in human and murine cutaneous immune responses.