Gelatinase expression at positive patch test reactions

Matrix metalloproteases (MMPs) are proteolytic enzymes involved in tissue remodelling and extracellular matrix (ECM) turnover. They are secreted in a latent form and activated at the cellular surface by a membrane type-1 MMP (MT1-MMP) and a tissue inhibitor of MMP-2 (TIMP-2) that is also responsible for striking a balance between the proteolytic enzymes and TIMP-2. In allergic contact dermatitis (ACD) patients, MMP-2 and MMP-9, two members of the MMPs family, were increased during the challenge phase, in involved but not uninvolved skin. In contrast, TIMP-2 was more evident in uninvolved than involved skin, while no differences were observed with regard to MT1-MMP staining. Comparing the serum of ACD patients with that of healthy subjects, these differences were not observed. These data suggest that MMP-2 and MMP-9 could play a role in the mechanisms inducing alterations of the epidermal architecture, and in the pathogenesis of the lesions.     

Usefulness of dermoscopy in the evaluation of patch test reactions

BackgroundDespite being widely used in different areas of dermatology, there have been few studies evaluating the benefit of dermoscopy in the interpretation of patch tests, especially in weak and doubtful reactions.ObjectivesTo evaluate the role of dermoscopy in the interpretation of patch tests and describe the main findings of the reactions.MethodProspective study, carried out in dermatology reference centers in southern Brazil, which evaluated the final results of patch tests analyzed with the aid of dermoscopy.Results77 patients and 160 reactions were included. The most prevalent substances were nickel sulphate (23.8%), kathon CG (9.4%), and perfume mix (8.8%). The main dermoscopic findings were reaction area​​ greater than half of the chamber site (90%), homogeneous erythema (86.9%), vesicles (30%), crusts (21.3%), perifollicular erythema (35%), pore reaction (19.4%) and pustules (8.8%). Dermoscopy was found to facilitate the definition of erythema in reactions on black skin and when due to substances with deposition of pigment. Of the 64 weak or doubtful reactions, 36 (56.25%) showed a change in the final result after dermoscopy evaluation; of the 36 doubtful reactions, 33 (91.6%) showed a change in the final result after dermoscopy evaluation (p < 0.001).Study limitationsThe probable limitation of the study is its sample size. Though certain significance levels have been reached, other possible relationships may not have been observed.ConclusionDermoscopy improves significantly the interpretation of patch tests, especially in weak and doubtful reactions.     

A clinical and patch test study of patients with positive patch test reactions to fragrance mix in China

The clinical and patch test (PT) features of patients with positive PT reactions to fragrance mix (FM) were studied. 378 consecutive eczema outpatients patch tested with a modified European standard series were analysed. 60 patients (15.9%) reacted to FM. No significant differences could be found between the ages of FM PT-positive and PT-negative patients [median age 40.5 (range from 18 years to 69 years) versus median age 37.5 (range from 5 years to 81 years), rank sum test, P = 0.301]. FM PT-positive rate in confirmed non-cosmetic allergic contact dermatitis patients was 30.4%, which was similar to that in confirmed cosmetic allergic contact dermatitis patients (30.4% versus 30%, chi(2) test, chi(2) = 0.0010, P = 0.972). The FM PT-positive rates were 10.8% in males and 18.2% in females (chi(2) test, chi(2) = 3.3443, P = 0.067). 76.7% of the patients with fragrance contact dermatitis were allergic to Chinese traditional medicine, which is much higher than that for cosmetic allergy (76.7% versus 43.3%, chi(2) test, chi(2) = 6.9446, P = 0.008). The positive PT rate to colophonium in the patients with positive PT reactions to FM is higher than that in the FM PT-negative patients (18.9% versus 3.0%, chi(2) test, chi(2) = 15.5471, P < 0.01). 62.5% of the patients reacted to colophonium were positive to FM. These results show that age has little effect on fragrance contact allergy. Other fragrant products besides cosmetics are also important sources of fragrance contact allergy. Chinese traditional medicine was an important factor in fragrance allergy in China. Patients with positive PT reactions to FM are more likely to react to colophonium.     

Selection of patch test materials for gold allergy

Allergic contact dermatitis to gold is very rarely reported. The occurrence of 2 recent cases in our department prompted a review of the literature, especially regarding the optimal reagents for patch testing. Gold chloride is most commonly used but may cause persistent dermatitis at the test site. Gold sodium thiosulfate is commercially available in petrolatum and is a reliable. non-irritant preparation for patch testing.     

Histologic aspects of patch test reactions in allergic contact dermatitis

Twenty subjects with allergic contact dermatitis were patch tested with the responsible allergen appliedtofour fixed points on the back. Skin biopsies of the four sites were obtained after 6, 12, 24 and 48 hours, fixed in neutral formalin and twined with hematoxylin-eosin, Giemsa and toluidine hint. Sections were examined and lymphomonocytes, mast cells, eosinophils and basophils counted. In all cases the infiltrate consisted mainly of lymphomonocytes (80–82 %); mast cells (5 %) and basophils (0.2 %) do not present clear variations within the given time. Eosinophils showed a definite numerical increase in six cases out of 20.     

Finn chamber patch test technique

Proper technique aids reliable patch test results. The Finn chamber volume was determined to be 25 microliters. These studies suggest the optimal volume semi-solid test substance to be 12-15 microliters. More than 18-21 microliters caused significant extrusion of test substance and improper adhesive adherence. Finn chamber paper discs used with solutions absorb a maximum of 17.5 microliters test solutions and keep 15 microliters within the chamber. The evaporation rate of aqueous test solutions from Finn chambers was 1 mg/3 min; thus, the chambers should be applied quickly to avoid drying.     

山东汉族梅毒患者与HLA-A、B等位基因的相关性研究

目的 探讨山东汉族梅毒患者与HLA-A、B等位基因的相关性.方法 采用PCR-序列特异性寡核苷酸探针杂交(PCR-SSOP)方法对205例山东汉族梅毒患者与5844例山东汉族正常对照的HLA-A、B等位基因表现频率进行检测.结果 梅毒患者组HLA-A*02,B*15、40等位基因频率高于对照组(P值均＜0.01;Pc值均＜0.05),HLA-A*26等位基因频率低于对照组(P=0.003;Pc=0.039),HLA-B*15、40等位基因频率在显性梅毒组高于对照组(P值均＜0.01;Pc值均＜0.05),HLA-A*02、11、29,B*15、40等位基因频率在隐性梅毒组高于对照组(P值均＜0.01;Pc值均＜0.05),HLA-A*30、33等位基因频率在隐性梅毒组低于对照组(P值、Pc值分别为0.002、0.026;0.001、0.013),HLA-A*30等位基因频率在显性梅毒组高于隐性梅毒组(P=0.001;Pc=0.013).结论 HLA-A*02,B*15、40等位基因可能与山东汉族梅毒相关,HLA-A*30可能与山东汉族显性梅毒相关,HLA-A*02、11、29可能与山东汉族隐性梅毒相关.

Abstract：

Objective To investigate the association of HLA-A and -B alleles with syphilis in Shandong Han population. Methods The allele frequencies of HLA-A and -B were detected in 205 patients with syphilis and 5844 normal human controls by PCR-sequence specific oligonucleotide probe (PCR-SSOP)method. Results The patients with syphilis showed a higher frequency of HLA-A*02, B*15, B*40 alleles(all P＜0.01, Pc＜0.05) and a lower frequency of HLA-A*26 allele (P= 0.003, Pc = 0.039) than the normal human controls did. There was an increased frequency of HLA-B*15 and B*40 alleles in patients with symptomatic syphilis (both P＜0.01, Pc＜0.05), as well as an elevated frequency of HLA-A*02, 11, 29, B*15 and 40 alleles (all P＜0.01, Pc＜0.05) and a decreased frequency of HLA-A*30 and 33 in patients with asymptomatic syphilis(P=0.002, 0.026, Pc=0.001, 0.013 respectively), compared with the normal human controls. The frequency of HLA-A*30 allele was significantly higher in patients with symptomatic syphilis than in those with asymptomatic syphilis (P = 0.001, Pc = 0.013). Conclusions There seems to be an association between HLA-A*02, B* 15 and B*40 alleles and syphilis, between HLA-A*30 allele and symptomic syphilis, and between HLA-A*02, 11 and 29 alleles and asymptom1atic syphilis, in Shandong Han population.     

HLA -A, -B, -C and -DR antigens in individuals with sensitivity to cobalt

In a skin investigation of 853 individuals working with hard metal manufacturing 39 cases of cobalt allergy were found. Thirty-five of the individuals with cobalt sensitivity and 102 matched controls were HLA-A, -B, -C and -DR typed. No significantly deviating HLA antigen frequencies were observed when the two groups were compared. Thus, there are no signs that a certain HLA antigen would dispose to cobalt allergy. In the cobalt sensitive group the B7 positive individuals showed particularly often simultaneous reactions to other contact allergens (p = less than 0.025). The B12 positive individuals had low reactivity (p = less than 0.0001) while the A28 positive showed high reactivity (p = less than 0.015).     

Disodium cromoglycate inhibits allergic patch test reactions

Disodium cromoglycate was applied before patch testing in patients with contact allergy to propipocaine hydrochloride, nickel and formaldehyde. The responses obtained were mitigated to a high degree when compared with similar effects due to corticoids.     

Allergic and irritant patch test reactions and atopic disease

This study presents a profile of patients with chronic recalcitrant eczematous disease referred by dermatologists for contact allergy evaluation. Allergic contact dermatitis (ACD) and irritant responses were carefully defined, as was the presence or absence of atopy obtained by history. Of 410 patients studied, 44% had no history of atopic disease and 46% were classed as definitely atopic. Among relevant ACD patch lest reactors ( n = 198). 51.5% had atopy, compared with 40.9% with no atopy but this difference was not significant. Likewise, among atopics ( n = 189). 54% had definite, relevant ACD patch test responses while 33.9% had negative ACD (again not significant). Significance was seen in the higher mean number of positive allergic patch tests in the atopic group (2.7 versus 2.0. p =0.0223). Irritant patch tests were highest among patients with both ACD and atopy ( p = U.0308) and the proportion of irritant responses correlated with increasing numbers of positive ACD tests. We conclude that atopics are at least as likely to have ACD as are non-u topics. Irritancy is increased in these patients with chronic dermatitis and the frequency of irritant reactions correlates with both greater numbers of ACD responses and with presence of atopy.