Isothiocyanates are important as haptens in contact allergy to chloroprene rubber

BACKGROUND

Contact allergy to chloroprene rubber products is well known. Thiourea compounds are considered the cause of allergy. Diethylthiourea commonly occurs in this type of product and can decompose to the sensitizer ethyl isothiocyanate.

OBJECTIVES

To investigate the clinical importance of degradation products and metabolites from organic thioureas in contact allergy to chloroprene rubber with a focus on isothiocyanates and isocyanates.

METHODS

Patients with contact allergy to diphenylthiourea were patch tested with phenyl isothiocyanate and phenyl isocyanate. Patients with known contact allergy to diethylthiourea were retested with diethylthiourea, while chemical analyses of their chloroprene rubber products were performed. The stability of diethylthiourea, diphenylthiourea and dibutylthiourea in patch-test preparations was investigated. Liquid chromatography/mass spectrometry and solid-phase microextraction/gas chromatography were used for determination of organic thioureas and isothiocyanates.

RESULTS

All patients allergic to diphenylthiourea reacted to phenyl isothiocyanate, two of eight reacted to phenyl isocyanate and six of eight reacted to diphenylthiourea. Four patients allergic to diethylthiourea reacted at retest; diethylthiourea was detected in all chloroprene rubber samples, with levels of 2-1200 nmol cm^-2 . At 35 °C, ethyl isothiocyanate was emitted from all samples. Patch-test preparations of diethylthiourea, diphenylthiourea and dibutylthiourea all emitted the corresponding isothiocyanate, with diethylthiourea showing the highest rate of isothiocyanate emission.

CONCLUSIONS

Thiourea compounds are degraded to isothiocyanates, which are generally strong or extreme sensitizers, thus acting as prehaptens. This process occurs in both chloroprene rubber products and patch-test preparations. Positive reactions to phenyl isocyanate indicate cutaneous metabolism, as the only known source of exposure to phenyl isocyanate is through bioactivation of diphenylthiourea.

An oral challenge test with carmine red (E120) in skin prick test positive patients

BACKGROUND

Positive skin prick test reactions to carmine red (E120) occur in approximately 3% of the patients studied for food allergy. Carmine ingestion associated systemic symptoms are occasionally suspected, but sufficient information of proven carmine allergy is not available.

PATIENTS AND METHODS

To analyse carmine related symptoms in skin prick test positive patients a cohort of 23 patients with suspected allergy to carmine red was subjected to a single-blind placebo-controlled oral challenge test with carmine red.

RESULTS

Five patients developed clinical symptoms during the placebo-controlled oral challenge. As a result, the overall frequency of clinical carmine allergy is estimated to be 0.7% in general dermatology patients studied for food-associated symptoms.

CONCLUSIONS

Oral challenge test provides a valuable in vivo tool to better inform patients with positive skin prick tests to additives to avoid false allergy diets.

An epidemic of furniture-related dermatitis: searching for a cause

Background Sitting in new chairs or sofas has elicited dermatitis in numerous patients in Finland and in the U.K. since autumn 2006. The cause of the dermatitis seemed to be an allergen in the furniture materials. Objectives To determine the cause of the dermatitis in patients with furniture-related dermatitis. Methods Altogether 42 patients with furniture-related dermatitis were studied. First, 14 Finnish patients were patch tested with the standardized series and with the chair textile material. A thin-layer chromatogram (TLC) strip and an extract made from the same textile material were tested in seven Finnish patients. The test positive spot of the TLC and the content of a sachet found inside a sofa in the U.K. were analysed by using gas chromatography-mass spectrometry. All chemicals analysed were patch tested in 37 patients. Results A positive patch test reaction to the chair textile and to its extract was seen in all patients tested, one-third of whom had concurrent reactions to acrylates. Positive reactions to the same spot of the TLC strip were seen in five of seven patients and dimethyl fumarate was analysed from the spot as well as from the sachet contents. Dimethyl fumarate (0.01%) elicited positive reactions in all the patients. The other chemicals analysed did not elicit positive reactions, but one patient in the U.K. had a positive reaction to tributyl phosphate. Conclusions Sensitization to dimethyl fumarate was seen in all the patients with furniture-related dermatitis. Concurrent sensitization or cross-reactions were common among the sensitized patients.

The usefulness of skin tests to prove drug hypersensitivity

BACKGROUND

Suspected drug hypersensitivity is common. Only a minority of cutaneous adverse drug reactions (CADRs) are allergic in origin and will reappear after the next exposure. Methods to confirm suspected CADRs are needed and skin testing could serve as one possibility.

OBJECTIVES

To analyse the usefulness of skin tests in revealing drug allergy. The relevance of skin test results was evaluated with drug provocation studies.

METHODS

During 1989-2001, 947 patients with a history of suspected CADR were examined with skin tests including patch tests (PTs) (826 patients), skin prick tests (SPTs) (935 patients) and photopatch tests (12 patients). The occurrence of positive and negative test reactions to different drugs was correlated with clinical history. Drug provocation was carried out in 246 patients.

RESULTS

Antimicrobial drugs were suspected and tested most often. A positive PT reaction to one or more drug was seen in 89 of 826 (10.8%), most often to beta-lactams, clindamycin and trimethoprim. A positive SPT reaction was seen in 10 of 935 (1.1%) patients. Challenge was carried out in 17 patients with positive skin test results. Thirteen of 16 (81.2%) PT positives developed exanthema, three remained negative and one SPT-positive patient developed urticaria. Among skin test negatives, 207 of 229 (90.4%) challenges were negative and 22 of 229 (9.6%) were positive, 12 with exanthema, three with fixed drug eruptions and seven with urticaria.

CONCLUSIONS

Skin testing, especially the PT, was a useful screening method to find a cause of CADR if the reaction was exanthema and if antimicrobial, cardiovascular or antiepileptic drugs were suspected. The SPT detected occasional positives with antimicrobials. In cases of fixed drug eruption, PTs performed at the earlier reaction site were useful. When skin tests are negative or dubious, oral challenge should be carried out to confirm the association.

Patch test reactions to cosmetic allergens in 1995-1997 and 2000-2002 in Finland - a multicentre study

Contact sensitivity to cosmetics is common, but the sensitizing chemicals vary between countries and study periods. The present survey aimed at revealing the recent trends in patch test sensitivity with cosmetic chemicals in Finland. We report a retrospective multicentre survey of patch test reactions focusing on cosmetic-related substances and comparing the test results in 1995-97 with those in 2000-02. The most striking increases in the frequency of the patch test sensitivity were found with balsam of Peru and propolis from 4.0% to 6.2% (P < 0.001) and from 0.5% to 1.4% (P < 0.001), respectively, whereas the most prominent decreases were found with methylchloro/methylisothiazolinone and chlorhexidine diglugonate from 2.4% to 1.3% (P < 0.001) and from 1.2% to 0.5% (P < 0.001), respectively. The level of patch test sensitivity to methyldibromo glutaronitrile increased, although not significantly, from 1.0% to 1.5%. An increasing tendency was also found with hair dye chemicals 4-aminophenol and toluene-2,5-diamine or toluene-2,5-diamine sulfate from 1.3% to 3.8% and from 1.4% to 5.2%, respectively, while such a tendency was not found among permanent wave chemicals. The sensitivity level of fragrance mix remained the same (6% - 7%). We conclude that surveys revealing the state of sensitivity to cosmetic chemicals should be performed periodically in different countries.

Presence of parvovirus B19 DNA in chronic urticaric and healthy human skin

BACKGROUND

The etiology of chronic urticaria is undefined, but the potential role of infectious agents as one triggering factor has been suggested. The appearance of chronic urticaria in a 16-year old male after a history of a recent parvovirus B19 (B19) infection led us to investigate the association between B19 and chronic urticaria.

OBJECTIVES

To investigate whether parvovirus B19 (B19) has a role in chronic urticaria.

STUDY DESIGN

We amplified B19 DNA from skin biopsy samples of 36 adult chronic urticaria patients as well as of 22 healthy controls using two sets of separate primers and probe. Circulating IgG and IgM antibodies to B19 were measured from 27 patients and from all controls.

RESULTS

B19 DNA was detected in 18 (50%) skin biopsy samples of 36 patients with chronic urticaria. Unexpectedly, also 14 (64%) skin biopsy samples from 22 healthy controls harbored B19 DNA. All 32 persons with positive B19 PCR findings had circulating IgG-class antibodies to B19 major structural protein VP2, but no IgM antibodies.

CONCLUSION

Our results show that B19 DNA commonly exists in human skin. Therefore, the association between B19 infection and chronic urticaria remains uncertain. However, these findings raise the question whether the skin may constitute a reservoir for B19.

Cutaneous adverse reactions to clindamycin: results of skin tests and oral exposure

BACKGROUND

Clindamycin is an antibiotic used in anaerobic and severe complicated infections. It is often selected for patients with a history of allergy to other antibiotics.

OBJECTIVES

To study the occurrence of clindamycin hypersensitivity and to determine whether skin tests are useful in cases of suspected clindamycin allergy.

METHODS

Six patients with an exanthematous rash and a history strongly suggestive of clindamycin hypersensitivity were studied with skin tests and oral exposure. Cases of suspected adverse drug reactions to clindamycin reported to the National Register of Adverse Effects of Drugs (NRAED) in Finland during 1973-2000 were analysed.

RESULTS

In the skin tests true-positive patch test reactions were seen in four of six patients, while 22 healthy control patients were negative. One false-positive and one false-negative patch test reaction were seen. During 1973-2000, 29 suspected cases of skin and/or mucosal membranes affected by clindamycin were reported to the NRAED.

CONCLUSIONS

Clindamycin hypersensitivity is not common. Delayed-type allergic reactions occur and patch tests are useful in those cases. Oral exposure is the method of choice if possible, as false-negative and false-positive reactions may occur.

A multicenter study of patch test reactions with dental screening series

BACKGROUND

Dental products contain many allergens, and may cause problems both for patients undergoing dental treatment and for dental personnel because of occupational exposure. Individual patch test clinics may not study sufficient numbers of patients to collect reliable data on uncommon allergens.

OBJECTIVE

To collect information on dental allergens based on a multicenter study.

MATERIALS AND METHODS

The Finnish Contact Dermatitis Group tested more than 4,000 patients (for most allergens, 2,300 to 2,600 patients) with dental screening series. Conventional patch testing was performed. The total number and percentage of irritant (scored as irritant [IR] or doubtful [?]) and allergic (scored as +, ++, or +++) patch test reactions, respectively, were calculated, as well as the highest and lowest percentage of allergic patch test reactions recorded by the different patch test clinics. A reaction index (RI) was calculated, giving information on the irritancy of the patch test substances.

RESULTS

The most frequent allergic patch test reactions were caused by nickel (14.6%), ammoniated mercury (13%), mercury (10.3%), gold (7.7%), benzoic acid (4.3%), palladium (4.2%) and cobalt (4.1%). 2-hydroxyethyl methacrylate (2.8%) provoked most of the reactions caused by (meth)acrylates. Menthol, peppermint oil, ammonium tetrachloroplatinate, and amalgam alloying metals provoked no (neither allergic nor irritant) patch test reactions.

CONCLUSION

Patch testing with allergens in the dental screening series, including (meth)acrylates and mercury, needs to be performed to detect contact allergy to dental products.

Is it possible to improve the prognosis in nickel contact dermatitis?

A questionnaire was sent to 143 patients who had shown a positive patch test reaction to nickel sulfate more than 10 years earlier. 91 patients returned the questionnaire, revealing that after the testing, 73 had suffered from dermatitis, 61 especially from hand dermatitis. 37 of these patients were clinically examined and patch tested with standard series and in addition, 12 patients were tested with nickel sulfate and nickel chloride with different occlusion times. At the clinic visit, 23 patients had dermatitis, 16 hand dermatitis, and 11 were symptom-free. 26 of the patients had metal items close to their skin and 21 of them had current dermatitis, 14 hand dermatitis. Of the 11 patients who had no metal exposure, 9 were symptom-free. The association of dermatitis with exposure to metal objects was statistically significant (p < 0.001). Those patients who had current dermatitis had also developed multiple allergies and reacted to nickel with shorter application times in patch tests, as compared to those who were symptom-free. It seemed possible that the prognosis for nickel dermatitis could be improved if nickel-allergic patients would strictly avoid metal contact, especially in clothing and jewelry.

Detection of parvovirus B19 in skin biopsy, serum, and bone marrow of a patient with fever, rash, and polyarthritis followed by pneumonia, pericardial effusion, and hepatitis

A previously healthy 33-year-old male patient presented with fever, rash and polyarthritis. Subsequently, he developed pleuropneumonitis, pericardial effusion and hepatitis. The diagnosis of parvovirus B19 infection was based on the detection of parvovirus DNA by PCR in a skin biopsy, bone marrow cells and serum. The patient had high parvovirus IgG antibody titres but remained negative for IgM at a three month follow-up, suggesting persistence of the virus or reinfection. It is concluded that detection of viral DNA is needed to verify a parvovirus B19 infection even in an immunologically healthy host.

Determination of IgE antibodies to Candida albicans mannan with nitrocellulose-RAST in patients with atopic diseases

A nitrocellulose-based radioallergosorbent test (RAST) was developed and used for the determination of IgE antibodies to Candida albicans mannan in patients with atopic dermatitis, asthma and allergic rhinitis. The results were expressed as mannan-RAST index values (an inter- and intra-assay coefficient for variation of 8.0-10.2%). The normal range for mannan-RAST index values was determined in 102 non-atopic adults. Fifty-three of 78 (67.9%) patients with atopic dermatitis showed elevated mannan-RAST index values with a significant correlation to the severity of the dermatitis (r = 0.33, P < 0.01). Sixteen of 30 (53.3%) patients with asthma had a positive mannan-RAST index value; however, 12 of the 16 asthmatics (75%) who were positive also suffered from atopic dermatitis. Those who had allergic rhinitis but not atopic dermatitis showed a positive mannan-RAST index value in 12 of 32 (37.5%) cases. Nitrocellulose-RAST offered a sensitive method for the determination of polysaccharide-specific IgE antibodies in atopic diseases. The results show that high values are observed mainly in atopic dermatitis and less sensitization to C. albicans occurs in respiratory allergy.

Candida albicans and atopic dermatitis

The role of sensitization and exposure to Candida albicans in atopic dermatitis (AD) was studied with skin-prick tests, yeast cultures and immunoblotting in 156 young adults with AD attending the Department of Dermatology, University of Turku, during 1983-89. Eighteen patients with allergic rhinitis without eczema and 39 non-atopics were included as controls. Parameters associated with severe AD were simultaneous anti-C. albicans IgE and saprophytic C. albicans growth. A statistically significant correlation between C. albicans sensitization (specific IgE antibodies) and AD symptoms was observed only in patients with saprophytic C. albicans exposure. No correlation between C. albicans-specific IgE and AD severity was shown in patients without gastrointestinal growth. Furthermore, severe eczema was seldom seen in patients without saprophytic C. albicans growth. The most important IgE-binding components of C. albicans in immunoblotting were 27 and 46 kD proteins and mannan, a polysaccharide. IgG and IgA antibodies to C. albicans, mainly towards C. albicans mannan, were found in practically all 70 sera studied. These results suggest a continuous exposure and induction of IgE antibodies by C. albicans in AD patients. Severe phases of AD in colonized patients are associated with IgE synthesis against C. albicans. These findings suggest a role for C. albicans in the exacerbations of AD but the clarification of this subject needs double-blind placebo-controlled treatment trials.

Does a patient's occupation influence the course of atopic dermatitis?

The importance of occupational environments in relation to the course of an atopic skin disease was investigated. A series of 1008 adult patients, who had had an atopic disease since their teenage years, were studied. Severe or moderate childhood atopic dermatitis tended to persist or relapse in adulthood independent of occupation. Only dermatitis of the hands showed a correlation with extensive daily exposure to occupational irritation factors. Atopic dermatitis patients did not go on sick leave more often than controls or those with atopic mucosal symptoms, although sick leave caused by skin problems lasted longer than sick leave caused by other circumstances. Atopic patients did not change their occupation because of their disease more often than the non-atopics. On the whole, changes in occupation were most common for patients without special education.

Skin prick test reactions to brewer's yeast (Saccharomyces cerevisiae) in adult atopic dermatitis patients

The sensitizing capacity of brewer's yeast (Saccharomyces cerevisiae) was studied with the skin prick test method in 449 subjects, including 226 atopic dermatitis (AD) patients, 50 patients with allergic rhinitis (AR) and/or asthma (A), and 173 nonatopic controls. A positive SPT reaction (> or = + +) was seen in 94% of patients with severe AD, in 76% with moderate AD, and in 25% with mild AD or no history of AD. Patients with AR and/or A and nonatopic controls displayed a positive reaction in only 8 and 2% of cases, respectively. There was also a parallel skin prick test reactivity with other yeasts including Pityrosporum ovale and Candida albicans, suggesting cross-reactivity. Parallel skin reactivity was observed also with molds and animal dander but not with pollen or house-dust mite. A significant correlation was also found between total serum IgE level and skin prick test (SPT) results with S. cerevisiae.

IgE-binding components of baker's yeast (Saccharomyces cerevisiae) recognized by immunoblotting analysis. Simultaneous IgE binding to mannan and 46-48 kD allergens of Saccharomyces cerevisiae and Candida albicans

The Saccharomyces cerevisiae allergens were characterized by IgE-immunoblotting with serum samples of 83 patients; 63 represented patients with atopic dermatitis with previous positive skin prick test or RAST for S. cerevisiae, seven patients with AD but negative test results and 13 were non-atopic controls. Disrupted whole body extract of S. cerevisiae was used in the assays. From the patients tested 41 patients with atopic dermatitis appeared positive in IgE immunoblotting revealing 22 IgE stained bands. From these bands 10 represented intermediate allergens, and 12 minor allergens. The most frequent staining was obtained with the 48 kD band (39%). When the staining pattern of 45 kD and 48 kD bands and mannan was compared with Candida albicans allergens or purified baker's yeast enolase a simultaneous binding was seen with the 48 kD band of S. cerevisiae and the 46 kD band of C. albicans and enolase whereas the 45 kD band was neither associated with the 46 kD band of C. albicans nor purified enolase. High molecular weight staining was found in five samples. The staining pattern was associated with the mannose containing structures in parallel with C. albicans.

Dose ranging study: cetirizine in the treatment of atopic dermatitis in adults

One hundred seventy-eight adults with atopic dermatitis were included in this double-blind, parallel, randomized study where the effects of placebo, and cetirizine, 10, 20, and 40 mg administered daily during 4 weeks were measured. Local rescue therapy, which consisted of emollients and 1% hydrocortisone, was permitted and patients in all four groups used it in the same regular way. Severity of atopic dermatitis was measured via the following parameters: pruritus (visual analog scales used by both the investigator and patients), four point scale (absent, slight, moderate and serious) symptom scores for erythema, vesicles, excoriation, and lichenification in 14 body areas and a final visit assessment of the patient's general condition. The patient's quality of sleep was also measured along with standard blood chemistry tests. Adverse events during the study were recorded as well. In total 127 patients were assessed for efficacy. A statistically significant (P < or = .05) improvement was observed in all therapeutic groups for the following parameters: erythema, excoriation, lichenification, total symptom score, area involved, and pruritus. Cetirizine showed a dose-related improvement in the following parameters measured: erythema, lichenification, total symptom score, area involved, final assessment, and pruritus (measured by the patient at each visit). At 40 mg, cetirizine was significantly (P < or = .05) more effective than placebo for these parameters. At 20 mg, this was true only for pruritus (measured by the patient at each visit).(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of atopic disorders among adolescents in Turku, Finland

A study of the prevalence of atopic disorders among 15-16-year-old teenagers was carried out in a coastal urban town in south-western Finland. Altogether, 1712 children were found in that age group, all previously examined by a pediatrician. Each child who had present or previous allergic diseases was invited for a detailed study, a total of 434 (25%) pupils. Of these patients 416 (95.8%) participated in clinical examination and skin testing. The prevalence of atopic diseases was 21% in the studied group; atopic eczema was found in 9.7%, allergic rhinitis in 14% and asthma in 2.5%. Of subjects who had rhinitis, 38% also had atopic eczema, while rhinitis--as the only symptom--was found in 8.8%. Figures obtained from this survey suggest that the prevalence rates of atopic diseases are about the same as found 10 years ago in Finland and they correspond also with other recent reports.

Patch test reactions in atopic patients

Patch testing was carried out in 851 atopic patients; 181 atopic dermatitis (AD) patients were additionally tested with 50% dilutions of the test substances. The occurrence of allergic and irritant reactions was frequent, being 57% and 33% for AD patients aged 28-41 years and 19-27 years, respectively. Among age-matched allergic rhinitis (AR)/allergic conjunctivitis (AC) or asthma (A) patients, the number of allergic reactions varied from 25 to 30%, and for irritant reactions was 24%. In all groups, nickel, fragrance-mix, balsam of Peru and neomycin were the commonest allergens. Contact allergy to ingredients of topical medicaments was common among AD patients and patients with severe and long-lasting dermatitis were most frequently sensitized. However, sensitivity to multiple substances was not common among those patients. The number of irritant reactions was considerable, but 50% dilution of the test substances did not solve the problem.

Effect of psoriasis heliotherapy on epidermal urocanic acid isomer concentrations

A noninvasive Finn Chamber sampling method and HPLC analysis were used to determine epidermal urocanic acid (UCA) concentrations of psoriasis patients during 4 weeks of heliotherapy on the Spanish Canary Islands and a follow-up period of 8 weeks. During heliotherapy the epidermal cis-UCA concentration increased from a mean initial value of 0.2 nmol/cm2 to a mean final value of 2.9 nmol/cm2. The total UCA concentration decreased during the first week of heliotherapy from an initial value of 5.5 nmol/cm2 to a nadir of 2.0 nmol/cm2. Thereafter, a steady increase was recorded in the total UCA level, with a maximum of 10.2 nmol/cm2 in week 2 of the post-treatment follow-up period. Suberythemal sun exposures caused near-maximal UCA isomerization, and during heliotherapy the cis isomer constituted 63.7-74.3% of the total UCA concentration. Clinical response of psoriasis to heliotherapy, however, seemed to be independent of UCA isomer levels.

Prognosis of atopic dermatitis. A prospective study in early adulthood

The course and development of atopic symptoms were followed up in 801 atopic dermatitis patients, in 207 allergic rhinitis or asthma patients, and in 517 control subjects. The patients were studied in the Dermatology Clinic during their teens and the follow-up studies were carried out at the ages of 22-41. Persistent or frequently relapsing dermatitis occurred in 77-91% of those who suffered from severe or moderate atopic dermatitis during their teens and in more than one half of those patients who only had mild dermatitis at the corresponding age. Atopic dermatitis had started in 13-17% of allergic rhinitis/asthma patients. At the time of the follow-up examination, severe dermatitis was seen in only six percent and moderate symptoms in 35% of atopic dermatitis patients. Dermatitis was generally seen in multiple loci: on the face, hands, extremities, and body. Deterioration of dermatitis in autumn and winter was experienced by one third to 88% of the atopic dermatitis patients. Psychic stress was experienced as a major aggravating factor in one half to two thirds of atopic dermatitis patients. Prick test positivity occurred in 62-89% of the dermatitis patients. Animal allergens, molds, grasses, birch, and house dust mite were the most common allergens. Associations between evident allergen exposure and deterioration of the dermatitis occurred in individual cases.

Lymphocyte migration into the skin: the role of lymphocyte homing receptor (CD44) and endothelial cell antigen (HECA-452)

Lymphocyte migration into the lymphoid organs and sites of inflammation is controlled by lymphocyte-endothelial cell interaction at sites where lymphocytes exit from the blood. Expression of Hermes-defined CD44 class of lymphocyte homing receptor and HECA-452 antigen specific for high-endothelium-mediating physiologic lymphocyte extravasation was studied in dermatitis herpetiformis, celiac disease, psoriasis, mycosis fungoides, lymphocytosis cutis, atopic dermatitis, and allergic contact dermatitis. Also, duodenal biopsies of patients suffering from dermatitis herpetiformis or celiac disease were studied for existence of these antigens. Infiltrating lymphocytes in the skin and in the duodenal area expressed homing receptor molecules when studied with monoclonal antibodies, Hermes-1 and Hermes-3, that recognize the CD44 class of molecules involved in lymphocyte binding to high endothelial venules in peripheral lymph nodes, mucosa-associated lymphatic tissues, and inflamed synovium. However, the HECA-452 antigen was not detected on the venules, neither in the skin nor in the duodenum. Even the venules possessing high endothelium morphologically were HECA-452 negative. These findings suggest the CD44 class of lymphocyte homing receptor(s) is also involved in lymphocyte homing to inflamed skin and the duodenal area of the gut. However, on the basis of HECA-452 staining, high endothelial venules in inflamed skin and duodenum are not antigenically identical with high endothelial venules in organized lymphoid tissues. This finding indirectly supports the idea that molecules and/or mechanisms mediating lymphocyte extravasation might be distinct in these organs.

Nickel sensitivity and the course of atopic dermatitis in adulthood

The course of dermatitis was followed in nickel-sensitive and nickel-negative atopic and non-atopic patients. Manifest dermatitis was seen in 70% of the nickel-allergic and in 64% of the nickel-negative female atopic dermatitis (AD) patients. Those atopic subjects who had minor symptoms in their teens suffered more from dermatitis if they had developed nickel allergy (p less than 0.025). Hands and the head region were the most common sites for current dermatitis in both groups.

Tendency to irritation: sensitive skin

The plausibility of the concept of "sensitive skin" evokes discussion and often amusement, because of the variance of the number of opinions compared with the amount of data, at least until recently. This report presents recent biologically oriented data that suggest that sensitive skin is a reality and is assessable with the use of contemporary methods.

PUVA treatment of nickel contact dermatitis: effect on dermatitis, patch test sensitivity, and lymphocyte transformation reactivity

Five females with nickel contact allergy and longstanding hand dermatitis were treated with oral methoxsalen and a series of whole-body UVA irradiations with a cumulative UVA dose of 30 to 58 J/cm2. Lymphocyte stimulation to nickel sulphate was determined prior to PUVA therapy, and monitored during the treatment and at 1 year after treatment. In 4 patients the cutaneous threshold to nickel sulphate patch testing was determined immediately post-PUVA and at 1 year. In all cases, the dermatosis cleared during the PUVA treatment. In 2 patients the immediate post-PUVA skin nickel reactivity was low compared with the 1-year follow-up value, while in 2 patients a progressive diminution of the skin reactivity was noticed. One patient was in clinical remission and had negative skin test at 1-year follow-up. In spite of diminished cutaneous sensitivity and/or clinical remission, the sensitivity of blood lymphocytes to nickel was approximately the same or increased, as determined by the lymphocyte transformation test. Thus no evidence was found to indicate that systemic, nickel-specific suppressive immune regulative mechanisms would have been activated by the treatment.

Mast cells and IgE in intestinal mucosa in adult atopic dermatitis patients

Duodenal biopsies from 29 adult atopic dermatitis (AD) patients with multiple positive skin prick test reactions were examined and the results compared with biopsies from 13 non-atopic controls. The duodenal mucosa showed mild inflammatory changes in six out of the 29 patients, but was normal in all the controls. Numerous anti-IgE positive cells, increasing with the severity of AD, were found in the duodenal mucosa in 25 of the 29 AD patients compared with few sporadic positive cells seen in only two out of 13 controls (P less than 0.001). The total serum IgE level showed a significant positive correlation with the number of anti-IgE stained cells in the mucosa (P less than 0.05). No significant differences were found in the total number of toluidine blue stained cells or cells immunoreactive for histamine between patients and controls. However, AD patients who had high numbers of anti-IgE positive cells often had decreased numbers of histamine immunoreactive cells in the mucosa suggesting mast cell degranulation. These findings provide further evidence that also in adult AD patients the gastrointestinal tract may serve as a portal of entry for allergens which may lead to exacerbation of AD.

Susceptibility to cumulative and acute irritant dermatitis. An experimental approach in human volunteers

Reactivity to repeated daily sodium lauryl sulfate (SLS) applications and patch test reactivity to SLS was studied in 23 females. Skin changes were quantified by transepidermal water loss (TEWL), dielectric water content (DEWC), laser Doppler velocimetry (LDV) and visual scoring (VS). Dermatologic histories (HS) and susceptibility to sunburn (ST) were obtained and clinical skin dryness evaluated (DS). Great interindividual variation occurred in the degrees of changes in the biophysical parameters measured: the variation was most apparent in TEWL. The subjects with HS 1 or more developed greatest TEWL increase after open SLS applications (p less than 0.05). DS showed poor correlation with SLS reactivity and only minor DEWC alterations were seen. ST showed some non-significant correlation with erythema reactivity in the patch test.

Dermatologic considerations in worker fitness evaluation

Dermatoses account for a very high percentage of all occupational diseases. The authors review individual factors that increase the risk of work-related skin disease and present information to assist in the evaluation of individuals in preemployment situations and for guidance and counseling prior to occupational choices.

Mechanisms of subjective (sensory) irritation. Propensity to non-immunologic contact urticaria and objective irritation in stingers

Subjective (sensory) irritation was studied with lactic acid test on 74 females; 8 reacted positively with "stinging" and/or itching or burning and another 5 had mild subjective sensations. History of previous corresponding sensations from contact with cosmetic products was significantly more common in stingers than in non-stingers (p less than 0.001); other factors, such as dermatologic history, sensitivity to ultraviolet light or skin dryness had no characteristic patterns. In the objective, immediate non-immunologic contact urticaria tests with sorbic acid and benzoic acid, the stingers developed significantly more erythema to 0.5% sorbic acid (p less than 0.05) and to 1% benzoic acid (p less than 0.02). 1% sorbic acid also induced more edema in stingers (p less than 0.02). Increased reactivity to a 24 h sodium lauryl sulfate (SLS) patch test was demonstrated only with laser Doppler velocimetry (p less than 0.05). Stingers and non-stingers reacted similarly to open, cumulative SLS irritation as measured with transepidermal water loss. These studies provide clinical and biological information about subjective irritation; the data suggest a functional correlation for the what had been considered a purely subjective (sensory) phenomena.

Irritant reactivity in males and females

Repeated, daily, open sodium lauryl sulfate (SLS) applications caused slight alterations in transepidermal water loss (TEWL) and dielectric water content (DEWC) in males and females. No erythema developed. Inter-individual variation in skin reactivity was demonstrated; sex-related patterns in reactivity to open cumulative irritant exposure did not exist. In patch testing with 0.5 and 1% SLS, reflecting acute irritation capacity, the reaction pattern, assessed by TEWL, DEWC, laser Doppler velocimetry (LDV) and visual scoring (VS), differed from that induced by open, cumulative SLS irritation. Again, inter-individual variation in the reactivity was demonstrated; significant sex-related differences did not develop. Individual reactivity showed considerable variation in acute and cumulative irritant response and was greater than the sex-related variation. We did not identify responses demonstrating that women have delicate (easily irritated) skin, nor that males have "tougher" skin than females.

Human cutaneous irritation: induced hyporeactivity

The variation in human skin response to sodium lauryl sulfate (SLS) was determined with patch and open applications. Reactions in different subjects and in multiple simultaneous patch tests were compared. Skin responses were assessed with visual scoring (VS), laser Doppler velocimetry (LDV) and transepidermal water loss (TEWL). Previous open, unpatched SLS exposure decreased patch test reactivity to 1% SLS assessed with VS (p less than 0.05) or LDV (p less than 0.05). Corresponding TEWL alteration was inconstant. Variation in reactivity at different test sites in multiple simultaneous tests was considerable, though less than the variation at different test times (p less than 0.05). Inter-subject variation in test reactivity was greater than the variation between different test times or adjacent test sites. Repeated open applications and the subclinical dermatitis appear to have produced a hyporeactive state. The results suggest that non-specific skin inflammation is elicited by multiple factors, e.g., stratum corneum integrity and vascular reactivity. Their balance determines the ensuing reactions. The induced hyporeactivity may be one of many causes of false negative diagnostic patch tests.

Do positive nickel reactions increase nonspecific patch test reactivity?

The patch test reaction pattern in nickel-positive and -negative female patients was compared. Cobalt allergy was found in 24.8% of the positive patients. However, the occurrence of allergy to other common agents, i.e., neomycin, perfume mix, balsam of Peru and bacitracin, did not differ significantly between the 2 groups. Even in patients allergic to nickel and cobalt simultaneously, the frequencies were comparable. Chromate and PPDA allergy was significantly commoner in nickel sensitive patients (p less than 0.05 and p less than 0.01). Erythematous or follicular reactions were seen most often to wood tars, propylene glycol, formaldehyde, cobalt, chromate and perfume mix. Reactions to propylene glycol and perfume mix were as frequent in both groups, whereas formaldehyde, cobalt and chromate caused reactions more often in nickel-positive patients (p less than 0.05) and wood tars in negatives (p less than 0.05). Follicular reactions developed especially in patients who were positive to nickel and cobalt. The total number of non-specific reactions was not overpresented in nickel sensitive patients, despite their multiple patch test reactivity.

Interrelationship of nickel and cobalt contact sensitization

The possible modulating effect of previous nickel sensitization on subsequent cobalt sensitization, and vice versa, was studied in a guinea pig model, using an open epicutanous induction protocol. Challenge tests were made by both topical and systemic routes. Controls included animals sensitized to only one of the metals. Animals sensitized with both metals seemed to react more readily in patch testing to either allergen, as compared to mono-sensitized animals. Systemic challenge with cobalt revealed a significantly (p less than 0.05) higher reaction rate (70%) in animals originally sensitized to cobalt and subsequently to nickel, as compared to the reaction rate (20%) in cobalt mono-sensitized animals. The reverse order of double-sensitization (nickel first, cobalt subsequently) led to an intermediate cobalt sensitization rate (50%). These experimental data corroborate clinical findings which have indicated a mutual enhancing effect of nickel and cobalt contact sensitization in man, and provide an animal model for studying the underlying immunological processes.

Experimental nickel sensitization in the guinea pig: comparison of different protocols

3 different sensitization protocols were compared for inducing delayed-type nickel contact hypersensitivity in guinea pigs. Open epicutaneous sensitization (OE) induced nickel allergy in 11/22 (50%) guinea pigs. When intradermal injections of Freund's complete adjuvant into the nickel-painted skin was added to the same protocol, 4/13 (31%) became sensitized. The guinea pig maximization protocol induced nickel allergy in only 7/31 (23%) of the animals. Compared with the 2 other methods, animals sensitized with open epicutaneous applications reacted more rapidly (maximum at 6 h) and strongly (2+ reaction in 12/22 of animals) in previous patch test sites upon systemic (i.p.) nickel challenge. Open epicutaneous sensitization of guinea pigs should be a useful model for studying cellular and immunological mechanisms in nickel contact sensitivity.

Nickel penetration in allergic individuals: bioavailability versus X-ray microanalysis detection

Development of local allergic reactions after different application times with Finn Chambers was recorded in 34 nickel-sensitive patients. Biologically significant amounts of nickel seemed to penetrate the skin within a few hours, although physical penetration was minimal. Nickel was detected only in the upper keratin cell layer with an X-ray microanalysis method.

24 and 48 h allergen exposure in patch testing. Comparative study with 11 common contact allergens and NiCl2

Patch test reactions to 11 common contact allergens were studied after 24 h and 48 h occlusion with Finn Chambers in 390 patients. Concordant allergic results were found in 96 cases (74%). In 22 patients (17%), the reaction was positive only after 48 h and in 11 cases (8.5%) only after 24 h exposure. Most of the discordant reactions were to nickel, cobalt, neomycin, formaldehyde and perfume mix. Irritant reactions were found in 55 cases, the majority occurring after 48 h occlusion. Nickel chloride tested in parallel with 48 h exposure lead to more positive allergic and toxic reactions than nickel sulphate.

Course of hand dermatitis in hospital workers

The occurrence and course of hand dermatitis in hospital workers was studied on the basis of the patient register of an occupational specialist and by a clinical follow-up study. About 1% of all the hospital workers had had dermatitis, cleaners, kitchen workers and nurses most frequently. 54% of the patients who were clinically studied had suffered from periodic symptoms and 35% had current hand dermatitis. Those who had previous or present atopic dermatitis had most frequently developed dermatitis during the first year of their service. An atopic constitution seemed to predispose to the development of permanent or periodic hand dermatitis. The patients with sensitivity to nickel or fragrances had relapses in the majority of cases. During the study period, the incidence of new dermatitis cases was constant, but the number of days sick leave showed a decreasing tendency.

Occurrence of contact allergy and hand eczemas in hospital wet work

The occurrence of contact sensitivity and hand dermatitis was studied in hospital employees. The incidence of contact allergy was 21%. Nickel (9%) was the most common allergen followed by perfumes (6%). Present of previous hand dermatitis was detected in 46%. Of those with positive reactions, 53% had suffered from hand dermatitis as compared to 44% of those without positive reactions. 70% of those with sensitivity to fragrances had suffered from hand dermatitis. The occurrence of hand dermatitis was more frequent in persons, who had developed contact allergy to rubber chemicals or to both nickel and cobalt simultaneously.

Atopy and hand dermatitis in hospital wet work

The relation of different atopic symptoms to the occurrence of hand dermatitis in employees who perform wet work in hospitals was studied. Atopy was defined as previous or present atopic dermatitis (AD), allergic rhinitis/conjunctivitis or asthma (AMS). In this population the prevalence of atopy was 32% and the frequency of past or present hand dermatitis 44%. Hand dermatitis had occurred in about 65% of persons with atopic symptoms and in 75% of those who had unusually dry, pruritic skin and of those with atopic relatives. Of the other workers only 33% had had skin problems. The presence of atopic symptoms significantly favoured the development of hand dermatitis in these occupations (p less than 0.001).

The pharmacokinetics of dapsone and acetylated dapsone in serum and saliva

The concentrations of dapsone (DDS) and its acetylated derivatives (MADDS and DADDS) were determined in the serum and saliva after one oral dose of dapsone until 72 hr. The peak serum concentrations of DDS and MADDS were reached, on average, at 3.8--4.3 hr after the dosage. The amounts of DADDS were negligible. The elimination half-life of the first order kinetics was, on average, at 20--21 hr for both DDS and MADDS. The study group included 6 rapid acetylators and 4 slow acetylators with the mean ratios MADDS/DDS 1.0 and 0.19, respectively. No difference in the pharmacokinetics of DDS or MADDS could be seen between the rapid and slow acetylators. The protein-free fractions of DDS and MADDS were 50 and 41 per cent, respectively, of the total serum concentrations as measured at 8 and 32 hr after the dosage. The salivary concentration of DDS was, on average, 49 per cent of the total serum concentration during the whole study period. The salivary concentration of MADDS was 40 per cent, respectively. The elimination half-life of DDS and MADDS in saliva did not differ from that in serum. Between the salivary and serum protein-free concentrations a strict correlation existed (p less than 0.001). The salivary concentration of dapsone and its monoacetyl derivative reflect the protein-free, active drug in serum.