Lack of cross-reaction between DNCB and chloramphenicol

Although one study has reported a cross-reactivity between DNCB and chloramphenicol in 40% of patients, other investigators have been unable to confirm the existence of any cross reaction. The purpose of this study is to determine whether sensitization of patients to DNCB poses a risk of cross reaction to chloramphenicol. In the present study, 100 consecutive patients who were sensitized to DNCB failed to show a single reaction to patch testing with chloramphenicol in a 1% ointment. The discrepancy between these results may be explained by a possible misinterpretation of a primary irritant reaction as an allergic contact reaction in the original report.     

Contact sensitization in chronic venous insufficiency: modern wound dressings

Patch tests with an expanded European standard series and 20 different wound dressings revealed sensitization in 78% of all (36) patients. The charts of allergens were headed by ointment bases (wool wax alcohols sensitization in 33% of all patients; Amerchol L-101 19.4%; cetearyl alcohol 13.9%; propylene glycol 8.3%), followed by plant resins/ethereal oils (balsam of Peru 22.2%; colophony 13.9%, fragrance mix 8.3%; propolis 5.6%) and topical antibiotics (neomycin sulfate 16.7%, chloramphenicol 13.9%), while usually common sensitizers like metal salts were not found as often (nickel sulfate 16.7%; potassium dichromate 13.9%; cobalt chloride 5.6%). Sensitization to modern wound dressings was found in 8.3% (3 cases) and was caused by propylene glycol as an ingredient of hydrogels; no sensitization was found to hydrocolloids, alginates or polyurethane foams. The overall sensitization rate in 2nd degree CVI was nearly as high as in 3rd degree CVI, but sensitization to ointments, their additives and topical antibiotics was significantly higher in 3rd degree CVI. Significant differences in sensitization frequencies to individual allergens were found between male and female patients. Our investigation points out the high risk of sensitization in 2nd as well as 3rd degree CVI, especially to ointment bases and active principles of topical drugs. Even wound dressings may cause allergic contact reactions.     

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.     

Sources of sensitization, cross-reactions, and occupational sensitization to topical anaesthetics among general dermatology patients

Background:  Contact sensitization to local anaesthetics is often from topical medicaments. Occupational sensitization to topical anaesthetics may occur in certain occupations.
Objectives:  The aim of the study was to analyse the occurrence of contact sensitization to topical anaesthetics in general dermatology patients.
Patients and Methods:  Patch testing with topical anaesthetics was carried out in 620 patients. Possible sources of sensitization and the clinical histories of the patients are analysed.
Results:  Positive patch test reactions to one or more topical anaesthetics were seen in 25/620 patients. Dibucaine reactions were most common (20/25), and lidocaine sensitization was seen in two patients. Six patients had reactions to ester-type and/or amide-type anaesthetics concurrently. Local preparations for perianal conditions were the most common sensitizers. One patient had developed occupational sensitization to procaine with multiple cross-reactions and with concurrent penicillin sensitization from procaine penicillin.
Conclusions:  Dibucaine-containing perianal medicaments are the major source of contact sensitization to topical anaesthetics. Although sensitization to multiple anaesthetics can be seen, cross-reactions are possible. Contact sensitization to lidocaine is not common, and possible cross-reactions should be determined when reactions to lidocaine are seen. Occupational procaine sensitization from veterinary medicaments is a risk among animal workers.     

Cross allergy between paranitro compounds with special reference to DNCB and chloramphenicol

Cross allergy between paranitro compounds including DNCB and chloramphenicol was studied in 42 patients. A total of 27 had been primarily sensitized to DNCB, and 15 patients with eczema exhibited a delayed-type reaction to chloramphenicol, showing u positive patch lest. All 15 patients with chloramphenieol allergy cross reacted with chloramphenicol succinate and chloramphenicol palmitate. Three of them cross reacted with paranitrobenzoic acid, and two of these also with paradinitrobenzene. None of the 15 patients cross reacted with DNCB in acetone or DNCB in petrolatum, and none reacted to picric acid, paranitrophtnol or dinitroorthocresol. The 27 patients primarily sensitized to DNCB did not cross react with any of the paranitro compounds studied, in particular not with chloramphenicol or its salts. Thus, the study confirms the specificity of the DNCB sensitivity.     

Eyelid edema as a predictive factor for sensitization to Pru p 7 in peach allergy

The clinical and laboratory factors related to Pru p 7 sensitization in peach allergy, compared with those associated with sensitization to Pru p 1, which is related to pollen‐food allergy syndrome (PFAS), have still not been clarified. The aim of the present study was to identify the clinical and laboratory features associated with sensitization to Pru p 7. Fifty patients (male : female, 14:36; mean age, 31.8 years) with peach allergy were enrolled in this study. Specific immunoglobulin E (sIgE) against the purified nPru p 7 was measured by enzyme‐linked immunoassay, whereas using ImmunoCAP, sIgE levels against peach, rPru p 1, rPru p 3 and rPru p 4 were measured. Correlations between the clinical characteristics of peach allergy and sensitization to the allergens were statistically analyzed. In 50 patients with peach allergy, 13 and 33 patients were sensitized with nPru p 7 and rPru p 1, respectively. Laryngeal tightness, conjunctival injection, facial edema, eyelid edema and urticaria were significantly associated with Pru p 7 sensitization. In contrast, oropharyngeal symptoms were strongly related to Pru p 1 sensitization but were significantly less common in the Pru p 7‐positive group. Co‐sensitization to the representative pollens related to PFAS, such as alder pollens, was significantly related to Pru p 1 sensitization, but not Pru p 7 sensitization. Along with the absence of co‐sensitization to pollens related to PFAS, facial edema and especially eyelid edema after the ingestion of peaches could be a predictive factor for sensitization to Pru p 7.     

420nm强脉冲光联合氯霉素搽剂治疗面部中重度痤疮疗效观察

目的观察420nm强脉冲光联合氯霉素搽剂治疗中重度寻常痤疮的疗效。方法将78例面部中重度寻常痤疮患者随机分为两组,观察组40例采用420nm强脉冲光联合氯霉素搽剂治疗;对照组38例单纯外用氯霉素搽剂治疗。结果观察组和对照组有效率分别为77．5％和47．37％,观察组疗效和有效率明显高于对照组（P〈0．01）。结论420nm强脉冲光联合氯霉素搽剂治疗中重度寻常痤疮的疗效优于单纯外用氯霉素搽剂。     

Allergic reactions to a hairdressers'series: results from 9 European centres

To obtain data on the frequency of sensitization among European hairdressers, the patch test results from 9 centres were evaluated. 8 allergens recommended by the ICDRG and EECDRG in the hairdressing series and PPD from the standard series were used to patch test 809 hairdressers and 104 clients suspected of contact sensitization. Among hairdressers, the mean frequencies of sensitization ranked as follows: GMT 19%, PPD 15%, APS 8%, PTD 8%, ONPPD 4%, and PADH 4%. In contrast to GMT in acid permanent waves, the frequency of sensitization to AMT in alkaline permanent waves was only 4%. Frequencies of sensitization to pyrogallol and resorcinol were 0.8% and 0.6%, respectively. The frequencies of sensitization showed marked regional variations, particularly that to GMT, which was highest in Germany (51%), followed by Spain (22%) and London (19%). Clients of hairdressers showed a similar rank order of sensitization frequency, with the exception of APS, which was completely negative in this (small) series.     

Occupational and non-occupational allergic contact dermatitis from beryllium

There are various references to sensitization to beryllium in the literature. Since introducing a patch testing series for patients with suspected sensitization to metals, we have found 3 cases of sensitization to beryllium. Of these 3 cases, we regard the first 2 as having relevant sensitization. Beryllium chloride (1% pet.) was positive in 3 patients and negative in 150 controls.     

Non-occupational contact sensitization to epoxy resin of bisphenol A among general dermatology patients

Background. Sensitization to epoxy resins often results from occupational exposure in various fields of construction and industry. Non‐occupational sensitization sources and environments have remained overlooked. Objectives. To analyse non‐occupational and occupational contact sensitization to epoxy resin of bisphenol A among general dermatology patients. Special attention was paid to patients sensitized from non‐occupational sources. Patients and methods. During a 10‐year period, 6042 general dermatology patients were patch tested with epoxy resin (bisphenol A) in the Dermatology Clinic of Turku University Hospital. The clinical data and the sources of occupational and non‐occupational exposure to epoxy resin were analysed in sensitized patients. Results. Epoxy resin sensitization was found in 59 patients. Non‐occupational sensitization was found in 21 (35%) patients, whereas the number of occupational cases was 38 (65%). The most common sources of non‐occupational epoxy resin sensitization were materials used in domestic renovation and construction projects and in boat repair. Conclusions. Non‐occupational sensitization sources account for approximately one‐third of epoxy resin sensitization cases, and therefore represent an important risk among hobbies and leisure activities.     

Comparison of guinea pig sensitization methods

Up to now, different methods in guinea pig sensitization were used, to assess contact sensitization potential of low molecular weight chemicals. In order to compare the efficiency of the epicutaneous, intradermal and combined sensitization methods, two stronger sensitizers, the water soluble chlormethylimidazoline hydrochloride (CMI) and the lipid soluble 1,3-dinitrochlorobenzene (DNCB) were used for the experiments. Eleven modified sensitization methods were performed. In a first trial each substance was tested on 10 animals. In a further study those techniques which had produced the best results, that is the highest degree of sensitization, were applied to 25 to 30 animals. For comparison of the results of the various methods, a mean sensitization index was calculated. The best results were achieved with the Maximization Test of Magnusson & Kligman (1969) and the Split Adjuvant Technique of Maguire & Chase (1967).     

Regulation of murine contact sensitivity to urushiol components by serum factors

Mice epicutaneously painted with components of poison ivy urushiol oil exhibit contact sensitivity (as detected by ear swelling reactions) that persist for about 25 days. Sera taken from mice at times when the contact sensitization response is waning suppressed the induction of sensitization to 3-n-pentadecylcatechol (PDC), a urushiol component, in recipients. The suppressive serum factor was present in greatest amount 25 days after sensitization, but was no longer detectable 40 days post sensitization. Suppression was antigen-specific, absorbed out with PDC-immune, but not normal lymph node cells, and transferable with a single 0.6 ml dose 7 days prior to sensitization of recipients. Suppression was transferable by the purified IgG fraction of desensitized mice. Results indicate that contact sensitivity to urushiol in mice is regulated by serum factors.     

Nickel sensitization and ear piercing in an unselected Danish population

The study aimed at evaluating nickel sensitization and ear piercing in an unselected population. A questionnaire and ready-to-apply patch tests (TRUE-Test) were mailed to 793 subjects, aged 15 to 69 years. A total of 567 (71.5% out of the 793) were patch tested. The tests were read 2 days after application. Nickel sensitization was diagnosed in 11.1% of the females and in 2.2% of the males. Independent of sex, old age was associated with a lower risk of nickel sensitization ( p <0.01). The risk of nickel sensitization was independent of a history of flexural eczema ( p >0.5). Ear piercing was more common in the young than in the older age groups, ranging from 30.5% to 0.0% in men, and from 91.5% to 42.9% in women, Sensitization lo nickel was found in 14.8% of those with pierced ears as compared to 1.8% among those without pierced ears. When adjusted for the effects of sex and age, the risk of nickel sensitization among those with pierced ears remained significantly increased and the odds ratio value was 4.5: the 95% confidence interval of the odds ratio value was 1.5 to 13.0. The study confirmed that nickel sensitization in the general population is common, particularly among women. Ear piercing is probably an important risk factor for nickel sensitization.     

Risk of sensitization to preservatives estimated on the basis of patch test data and exposure, according to a sample of 3541 leave-on products

Background. The risk of sensitization cannot be derived from the frequency of sensitization to allergens alone, but exposure should be considered. Objective. To estimate the risk of sensitization to selected preservatives. Methods. The occurrence of preservatives in 3541 leave‐on products based on the labelling of the ingredients was documented. Frequency of sensitization to preservatives was analysed on the basis of Information Network of Departments of Dermatology data for 2006–2009. As an estimate of sensitization risk, the sensitization exposure quotient (SEQ) was calculated as the quotient of the relative frequency of sensitization and the relative frequency of use. Results. The SEQs varied greatly, offering a ranking regarding risk of sensitization: phenoxyethanol (SEQ: 0.06), benzyl alcohol (0.30), parabens (0.35), sorbates (0.92), benzoates (1.35), formaldehyde‐releasers (1.6), methylisothiazolinone (MI) (1.7), iodopropynyl butylcarbamate (3.4), methylchloroisothiazolinone/MI (9.0), and 2‐bromo‐2‐nitropropane‐1,3‐diol (13). There was a good correlation between the ranking of substances according to potency (hazard) and the ranking of the SEQ (risk). Conclusion. High frequencies of sensitization may be put into perspective by the frequent use of certain preservatives. Despite infrequent use, others (with higher potencies or too high use concentrations) may turn out to be associated with an increased risk. Hazard assessment should be supplemented by risk assessment.     

Contact sensitization of mice to nickel sulphate and potassium dichromate

The ability of nickel sulphate and potassium dichromate to induce contact sensitization in mice has been investigated. Topical exposure of mice to 0.5% potassium dichromate in dimethylsulphoxide (DMSO) under occlusion resulted in specific contact sensitization in each of 7 experiments. Although sensitization to nickel sulphate under the same conditions was weak and somewhat variable, evidence for significant levels of contact allergy was obtained in 4 of 7 experiments. In addition, repeated topical application of both nickel sulphate and potassium dichromate in DMSO was found to result in the induction of lymphocyte proliferative responses in lymph nodes draining the site of exposure. These data indicate that epicutaneous exposure to both metal salts may cause specific contact sensitization in mice.     

The use of gloves in Australian dermatological practice

Dermatologists use gloves as a major tool in universal precautions to prevent transmission of infections particularly human immunodeficiency virus (HIV) and hepatitis. We need to know how much protection is conferred by gloves and what problems are associated with glove use. This paper looks at these issues and reports the results of a survey on glove use by Australian dermatologists. The survey found a lack of awareness regarding gloves as a protective measure, suggesting the need to improve knowledge in this area so that realistic precautions can be adopted. Dermatologists have a high rate of glove use and reactions to gloves were noted by 13% of respondents. The authors recommend the use of non-powdered, low-allergen latex gloves. Handwashing prior to using non-powdered latex gloves needs further investigation. Handwashing after wearing latex gloves may decrease sensitization risk.     

The sensitizing capacity of the antioxidants propyl, octyl, and dodecyl gallate and some related gallic acid esters

8 alkyl gallates, including the widely used antioxidants propyl, octyl, and dodecyl (= lauryl) gallate, have been subjected to experimental sensitization in guinea pigs. Using a modern sensitization procedure, the results showed that all gallates are moderate to strong contact sensitizers: dodecyl (= lauryl) gallate was found to be the strongest. A characteristic correlation between side chain length and mean response was observed, giving a maximum of sensitization at a length of 12 carbon atoms (dodecyl gallate). A literature review revealed that the frequency of reports of allergic contact dermatitis from antioxidants of the gallate type has increased in the last 4 years. In most cases, the moderate sensitizer propyl gallate was the source of sensitization.     

Hyposensitizing therapy with standard antigenic extracts: an important source of thimerosal sensitization

The frequency of thimerosal sensitization was determined in 5 groups of subjects: military recruits; healthy subjects; patients with asthma or rhinitis undergoing hyposensitizing therapy with thimerosal-preserved antigenic extracts; patients with allergic contact dermatitis; patients with allergic contact conjunctivitis. Our patients with allergic contact dermatitis have a higher incidence of positive patch tests to thimerosal than healthy subjects. The source of thimerosal sensitization in this group remains obscure, their history of exposure to this or to other mercury derivatives being comparable to that of the healthy population. Patients with allergic contact conjunctivitis and patients receiving immunotherapy for asthma or rhinitis present a significantly higher frequency of thimerosal sensitization than the other groups, indicating that ophthalmic solutions and thimerosal-preserved allergen extracts are an important source of thimerosal sensitization. The clinical relevance of thimerosal sensitization was definitively established only in patients with allergic contact conjunctivitis, even though patients receiving immunotherapy frequently presented local reactions at the site of allergen inoculation.     

Chronic urticaria is associated with a differential helminth-arthropod-related atopy phenotype

The relationship between atopic sensitization and chronic urticaria is still controversial. In this study, we aimed to compare the prevalence of aeroallergen sensitization in chronic urticaria patients with (CU/As+) and without (CU/As-) sensitization against Anisakis simplex. Forty-nine CU/As+ and 80 CU/As- patients were studied and skin prick tests (SPT) were performed against aeroallergens. We assessed sensitization in a subgroup of patients with allergic rhinoconjunctivitis and/or bronchial asthma (RCBA) and compared the prevalence with a control group of 522 non-urticaria patients with RCBA. Forty-five percent of CU/As- and 60.4% of CU/As+ patients displayed positive SPT to at least one aeroallergen. CU/As+ patients had a higher prevalence of sensitization against pollen, mould or dander (PMD) (52.2% vs 29.1%, P < 0.01), whereas the prevalence of house dust mite (HDM) sensitization was not statistically different (26.3% in CU/As- and 36.7% in CU/As+). However, in chronic urticaria patients with RCBA, 53.8% of CU/As- and 57.9% of CU/As+ patients differed in the prevalence of HDM sensitization compared to the control group (33.5%, P = 0.03), whereas no difference could be stated for PMD sensitization. Compared to RCBA patients, both CU/As+ and CU/As- patients have a higher clinically relevant sensitization rate against HDM, thus displaying a differential atopy phenotype.     

Hairdressers' eczema--results of expert assessment 1984-1987

The following study is based on the evaluation of 116 expert opinions obtained between 1984 and 1987 regarding patients working as hairdressers and suffering from eczemas. The most frequent allergen was nickel sulfate (57.7%). Exclusive nickel allergy without sensitization to substances professionally used, however, was only found in 6.9% of the female patients tested. Nickel allergy associated with sensitization to such substances was observed in 50.5% of the patients. 90 out of the 116 persons tested showed positive reactions to the indicator substance used in the hairdressers' trade and/or to the substances actually used during their work. Exclusive sensitization to one or more substances of the indicator group (occupationally used substances negative) was found in 13.3% of the patients; exclusive sensitization to substances actually used (indicator group negative) was seen in 16.7%.