Mini-epidemic of contact dermatitis from ginkgo tree fruit (Ginkgo biloba L.)

3 cases of contact dermatitis from ginkgo fruit are reported. Swelling of the prepuce can be the only clinical sign of intolerance, as was observed in 1 case. Diagnosis of contact dermatitis to ginkgo fruit should be made in cities where female ginkgo trees grow, in Chinese, Japanese and South-East Asian subjects, who are aware of the ginkgo nut's culinary qualities within the fruit, as well as in children who play with the fallen fruits as "marbles".     

Regulation of the contact sensitivity response to urushiol with anti-urushiol monoclonal antibody ALG 991

The objective of the studies was to demonstrate that the contact sensitivity (CS) response to poison ivy/oak could be downregulated following treatment with a monoclonal antibody (mAb) reacting with the allergen urushiol. Conjugation of urushiol and its synthetic analogue 3-n-pentadecylcatechol (PDC) to N-acetylcysteine yielded hydrosoluble derivatives which induced humoral immune responses in BALB/c mice. Hybridomas secreting monoclonal antibodies (mAbs) reacting with urushiol and PDC were generated by fusion of B lymphocytes from immunized mice with mouse myeloma P3NS0 cells. The specificity of mAb ALG 991 (IgM isotype) was defined by inhibition of antibody binding by PDC analogues. This demonstrated that mAb ALG 991 reacted with the catechol moiety of urushiol, the region of the allergen being critically important in the induction of contact dermatitis. The CS response to urushiol in BALB/c mice was suppressed by stimulation with mAb ALG 991 and the role of sensitized T cells, including suppressor T cells, has been considered. Suppression of CS was most effective with low doses (1 microg) of mAb incorporated into a vaccine with Freund's adjuvant. This treatment suppressed CS responses in BALB/c mice already sensitized to urushiol.     

Allergic contact dermatitis to laurel (Laurus nobilis L.): Isolation and identification of haptens

Summary Two methods, using methylenelactone dimethylamino adducts, were used to remove selectively -methylene -butyrolactones from Laurus nobilis L. extracts. Isolated lactones were identified and treated extracts recovered. Two guinea-pig groups were sensitized to crude extracts and treated extracts, respectively, and tested with primary sensitizer and with different lactones. Only the first group showed strong skin reactions to crude extracts and to the lactones. Treated extracts were shown to be anallergic.     

A further characteristic of susceptibility to contact allergy: sensitization to a weak contact allergen is associated with polysensitization. Results of the IVDK

Although genetic factors probably account for differences in susceptibility to contact allergy, they have not yet been identified, partly due to an insufficient understanding of 'susceptibility'. Regarding polysensitization (PS) as a sign of increased susceptibility, we studied the relationship between PS and sensitization to weak versus strong allergens. Patch test data from 66,835 patients registered by the multicentre project, Information Network of Departments of Dermatology (IVDK) between 1 January 1997 and 31 December 2004, were analysed. The association between the number of sensitization to standard series allergens, and contact allergy to a strong allergen methyldibromoglutaronitrile (MDBGN) and to a weak allergen (paraben mix), was analysed with adjusted logistic regression analysis. In paraben-positive (++/+++) patients, the risk of > or = 2, > or = 3 or > or = 4 additional reactions were significantly increased by a factor of 2.1-4.6 compared to MDBGN-sensitized (++/+++) patients. Varying the basic model, a higher risk of additional positive reactions associated with paraben sensitization was consistently identified. The association between PS and sensitization to weak allergens adds a further characteristic of susceptibility to former findings of the IVDK, where PS was related to an increased risk of induction, elicitation, and cytokine polymorphisms. PS can be regarded as a phenotype to be considered in genetic studies.     

Contact sensitivity in patients with venous leg ulcers in Serbia: comparison with contact dermatitis patients and relationship to ulcer duration

Background: Contact hypersensitivity is a common occurrence in patients with chronic venous leg ulcers (CVLU) with allergen profiles depending upon the local treatment policies.
Objective: This study was to determine the frequency of contact sensitivity, prevalence of individual allergens, polyvalent sensitization, and/or their relationship to ulcers duration in the population of CVLU and contact dermatitis patients in Serbia.
Patients: 75 patients with CVLU and 82 patients with clinically suspected contact dermatitis were prospectively included in the study. The patients were patch tested with a series of 21 standard and 22 supplemental allergens.
Results: 73% ( n  = 55) of CVLU and 52% ( n  = 43) of control subjects had 1 or more positive patch test results ( P  < 0.01). Polysensitization was found in 53% of patients and 21% of controls ( P  < 0.01). CVLU patients run 2.5 and 4.3 higher risk for contact sensitization and polysensitization, respectively. The most common allergens were Balsam of Peru (21.3%), carba mix (18.7%), fusidic acid (17.3%), colophony (13.3%), paraben mix (12%), chloramphenicol (12%), silver nitrate (12%), and neomycin (10.7%). Polivalent sensitization and higher mean number of allergens were associated with ulcer duration >5 years.
Conclusions: The results confirm a high rate of contact (poly)sensitization in patients with CVLU and local variability in allergen prevalence.     

Reduced proliferative responses of peripheral blood mononuclear cells specifically toCandida albicans antigen in patients with atopic dermatitis — comparison with their normal reactivity to bacterial superantigens

Although reduced cutaneous reactivities toCandida, albicans have been reported in patients with atopic dermatitis (AD), there is still controversy as to whether the in vivo lymphocyte proliferation response is normal or reduced. We have also reported that patients with AD manifest a decreased cutaneous response only toC. albicans antigen in scarification patch tests. The purpose of this study was to examine whether patients with AD show normal lymphocyte transformation responses toC. albicans antigen. Peripheral blood leucocytes (PBL) from 21 patients with AD and 14 healthy control (HC) subjects were cocultured with optimal concentrations ofC. albicans antigen and of superantigens (staphylococcal enterotoxin A and B). PBL from the patients with AD showed a significantly lower response toC. albicans antigen, but there was no statistically significant difference, in PBL responses to superantigens between the patients with AD and the HC subjects. This decreased proliferative response of PBL was particularly noticeable in those whose RAST scores forC. albicans antigen were high. These results suggest the development of a specific anergy toC. albicans antigen in patients with AD.