Toxische Kontaktdermatitis auf Poison Ivy in einem Privatgarten in Deutschland

A couple suffered for 5 years from recurrent eruptions with vesicles and bullae after contact with an unknown "climbing weed" in their private garden in Germany. After this plant was identified as poison ivy and eradicated, their skin problems were solved. This is the first report of poison ivy in this setting. Urushiols in poison ivy are not only strong allergens but also potent irritants. Negative patch tests in the husband suggest that the bullous dermatitis was a toxic reaction.

Absence of contact sensitization to Aloe vera (L.) Burm. f

Aloe vera has been used as a cosmetic and medical remedy since ancient times and has gained increasing popularity in recent years. Despite its widespread use, reports of allergic reactions are rare. We patch tested 702 consecutive patients with an oily extract from the leaves, Aloe pulvis from the entire plant and concentrated Aloe vera gel. A specially designed questionnaire was used for the use of Aloe vera, reasons and location of application, adverse reactions, occupation, hobbies and atopy. None of the subjects showed any reaction to one of the preparations. 2 components of the plant have to be distinguished: the bark of the leaves contains anthrachinones with pro-peristaltic and potential antibiotic and anticancer properties. Constraints have been imposed due to their considerable toxic potential. Today, mostly the Aloe gel from the center of the leaves is processed. It almost exclusively consists of carbohydrates to which also many medical effects have been attributed. Carbohydrates are not likely to induce contact sensitization, which might explain the outcome of our study. However, this does not justify unrestrained promotion of Aloe products, as scientific studies investigating the claims on its constitutional effects are few in number, and the majority of them have been unable to diminish the intuitive scepticism against miracle cures, like Aloe seems to be.

Contact vitiligo following a strong patch test reaction to triglycidyl-p-aminophenol in an aircraft industry worker: case report and review of the literature

Epoxy resin systems (ERSs) are a frequent cause of occupational allergic contact dermatitis. A 50-year-old patient developed eczematous skin lesions on the back of his hands, lower arms and eye lids, 2 months after he had started working in aircraft construction. Patch tests showed positive reactions at day 3 to nickel sulfate, epoxy resin based on diglycidyl ether of bisphenol F (DGEBF) and 1,4-butanediol diglycidyl ether (1,4-BDDGE). The chemical triglycidyl-p-aminophenol (TGPAP) applied at 1% and 0.1% induced the strongest (+++ positive) reaction. About 4 months after the patch test with TGPAP, the patient presented with 2 circular depigmented spots in the former TGPAP-patch test areas. Dermatohistopathology confirmed the diagnosis of contact vitiligo.

Fondaparinux: a suitable alternative in cases of delayed-type allergy to heparins and semisynthetic heparinoids? A study of 7 cases

Hypersensitivity to unfractionated and low-molecular-weight heparins and semisynthetic heparinoids is increasingly common. 7 female patients between 30 and 74 years with delayed-type allergy to heparins and semisynthetic heparinoids were investigated for (cross)-reactivity to fondaparinux, a new pentasaccharide with selective factor Xa inhibition. All patients showed delayed-type reactions to heparins and some additional cross-reaction to a heparinoid on intracutaneous testing. 6/7 tolerated fondaparinux on intradermal testing as well as on subcutaneous challenge testing. However, the 7th patient developed a characteristic delayed-type reaction to both skin tests with fondaparinux. Fondaparinux is a new synthetic pentasaccharide with a molecular weight of 1.728 Da. In some patients with cross-reactivity between various heparins and semisynthetic heparinoids, lepirudin, a recombinant hirudin, may be a safe and effective alternative. However, combined allergy to hirudin and heparins has been reported. Sometimes, intravenous administration of heparins or heparinoids may be tolerated. However, these patients are at risk of developing a systemic reaction. The pathogenesis of heparin hypersensitivity is not fully understood. Heparins may act as haptens by binding to dermal and/or subcutaneous structural proteins. The chemical structures of heparins and fondaparinux are different concerning their alpha- and beta-configuration and the molecular weight. However, some of their functional groups are nearly identical and therefore similar chemical and pharmacological reactivity is to be expected. Fondaparinux seems to be a valuable alternative in most cases of heparin and hirudin hypersensitivity. The clearly rare cross-reaction between fondaparinux and heparins, now confirmed by us, may be due to differences in the response to haptens.

[Epidemiologic surveillance of contact allergens. The "monitoring series" of IVDK (Information Network ofDermatologic Clinics for Detection and Scientific Evaluation of Contact Allergy]

The selection of the most important contact allergens is subject to a continuous change. Several factors may influence the sensitization rates and thus the decision, which substances to include in the standard series of the most frequent allergens. The Information Network of Departments of Dermatology adds substances of interest for a certain time period to the standard series in order to evaluate parameters such as sensitization rate, grade of reaction, and clinical relevance of positive reactions. In 6 testing periods starting in 1996, 13 test substances were evaluated. Due to the results, propolis, compositae mix, and bufexamac were included in the standard series in 1999, while lyral was added in 2002. Sorbitansesquioleat, dispers blue mix, and iodopropynyl butylcarbamate are under further discussion. Substances such as glutaraldehyde and p-aminoazobenzole should be tested in certain risk groups only, whereas the steroids budesonide and tixocortol should be tested when clinically suspected.

Sensibilisierung auf Teebaumol in Deutschland und Osterreich - Eine multizentrische Studie der Deutschen Kontaktallergiegruppe. Sensitization to tea tree oil in Germany and Austria. A multicenter study of the German Contact Dermatitis Group

BACKGROUND AND AIM

Tea tree oil, a distillation product of the Australian tea tree (Melalence alternitolia) is increasingly used as an alternative remedy for various dermatological diseases. Tea tree oil contains several allergenic monoterpenes and sesquiterpenes. In this multicenter study it was evaluated, whether the increasing use of tea tree oil has lead to an increased frequency of sensitization in Germany and Austria which would justify its inclusion into the standard series.

PATIENTS AND METHOD

For patch testing a standardized tea tree oil was used, dissolved 5% in diethylphtalate (DEP). Consecutive patients of 11 dermatological departments in Germany and Austria were tested. Readings were taken on day 2 and 3 according to the guidelines of the German Contact Dermatitis Research Group (DKG).

RESULTS

5% tea tree oil was positive in 36/3375 patients (1.1%). Sensitization frequencies showed great regional variations and ranged from 2.3% (Dortmund), 1.7% (Buxtehude), 1.1% (Essen), 0.7% (Graz), to 0% (Berlin, Vienna). 14/36 patients (38.9%) also showed a positive patch test reaction to oil of turpentine.

CONCLUSION

Our results show that tea tree oil is an important contact allergen for some centers. It should be tested, if medical history suggests its previous use. Considering the great regional differences in frequencies of sensitization its inclusion into the standard series is not recommended yet.

The seamy side of natural medicines: contact sensitization to arnica (Arnica montana L.) and marigold (Calendula officinalis L.)

Medical remedies of plant origin have gained increasing popularity in recent years. Both anaphylactic and eczematous allergic reactions are on the rise, accordingly. Arnica and marigold, both of the Compositae family, are in widespread use, but only limited data are available on their allergenic potential. We tested 443 consecutive patients, in addition to the European standard and other series, with Compositae mix, sesquiterpene lactone mix, arnica, marigold, and propolis. 5 subjects ( approximately 1.13%) reacted to arnica, 9 ( approximately 2.03%) to marigold. The Compositae mix was positive in 18 cases ( approximately 4.06%). Among them were 3 out of 5 individuals with a sensitization to arnica, and 4 out of 9 who reacted to marigold. Sensitization to arnica and marigold was often accompanied by reactions to nickel, Myroxylon Pereirae resin, fragrance mix, propolis, and colophonium. We conclude that Compositae allergy contributes significantly to the epidemiology of contact dermatitis and that sensitization to arnica and marigold cannot be assessed by testing with the Compositae or sesquiterpene mix alone. As extracts of these plants are frequently used in occupational and cosmetic products, patch testing with additional plant extracts or adjustment of the commercial Compositae mix to regional conditions is recommended.

Sensitization and cross-reaction patterns in Danish Compositae-allergic patients

Results of aimed patch testing with constituents of sesquiterpene lactone (SL) mix, Compositae mix (CM) and other Compositae extracts and allergens in 190 Compositae-allergic patients detected in an 8-year period are presented. Feverfew of CM elicited positive reactions most frequently, followed by tansy, wild chamomile, yarrow and arnica, whereas dehydrocostus lactone of SL was the most frequent elicitor of positive reactions, followed by alantolactone and costunolide. Chrysanthemum (Dendranthema) and marguerite (Argyranthemum frutescens) were the most important suspected sensitizers in both occupationally and nonoccupationally exposed, and cross-reactions between chrysanthemum and feverfew/tansy/chamomile may partly explain the high prevalence of positive reactions to the 3 last mentioned. In the nonoccupationally sensitized group, garden plants such as feverfew, blanket flower (Gaillardia), elecampane (Inula helenium), large yellow ox-eye (Telekia speciosa) and cosmea (Cosmos) were additional important allergenic plants. The 3 last mentioned were picked up by SL mix. Most of the lettuce-sensitized persons were CM-positive. 19% of the occupationally sensitized group were negative to both SL and CM, making very aimed patch testing necessary, notably when suspecting rare sensitizers such as Gerbera and star of the veldt (Osteospermum). The significance of the weeds dandelion, dog fennel and ox-eye daisy as sensitizers is not clarified, but they are probably less important than cultivated plants.

An 8-year experience with routine SL mix patch testing supplemented with Compositae mix in Denmark

Routine patch testing with sesquiterpene lactone (SL) mix, supplemented with Compositae mix (CM) and other Compositae extracts and allergens where appropriate, was evaluated over an 8-year period. 190 of 4386 patients tested (4.3%) were Compositae-sensitive, 143 females (mean age 51.5 years) and 47 males (mean age 55 years), and 83% of reactions considered clinically relevant. 22% were suspected of occupational sensitization/dermatitis. 62% had a contact allergy to 2 or more compounds, most often to nickel, fragrance and colophonium. SL mix detected 65%, CM 87% of Compositae-allergic patients, and the overall detection rate with both mixes was 93%. Few irritant reactions and no cases of clear-cut active sensitization were recorded with the mixes, but our results emphasize the importance of differentiating late-appearing reactivation reactions from patch test sensitization. The weakly positive CM reactions could reflect some irritancy, but as they were associated with fragrance and/or colophonium allergy to a higher degree than weakly positive SL mix reactions, they probably represented cross-reactions. In conclusion, the detection rate with SL mix was high enough to support its continued use as a screening mix and it was very well and rather safely supplemented by aimed testing with CM.

Contact allergy to balsam of Peru. II. Patch test results in 102 patients with selected balsam of Peru constituents

BACKGROUND

In Switzerland, Germany, and Austria, allergic reactions to balsam of Peru (BP) have now made it the third most common contact allergen.

OBJECTIVE

A series of 20 single BP constituents (including resorcinol monobenzoate), established in 1995, was used for patch tests in patients with a positive reaction to BP in the standard series.

MATERIALS AND METHODS

Between 1995 and 1998, 2,273 patients were tested with the standard series, including BP, fragrance mix (FM), and propolis. Patients positive for BP were requested to participate in a further test using the 19 compounds of the BP constituents and resorcin monobenzoate (BP series); 102 patients agreed and were patch tested. The results of the 72-hour reading were used for the evaluation.

RESULTS

A total of 93 patients reacted to 1 or more of the BP series compounds. Positive reactions were seen, in decreasing order, to cinnamic alcohol, cinnamic acid, coniferyl benzoate, benzoic acid, cinnamyl cinnamate, eugenol, resorcinol monobenzoate, coniferyl alcohol, and benzyl alcohol. There were no positive reactions to vanillin or ferulic acid. A correlation between skin lesions and frequent consumption of sweets was found in 7 patients with major positive test reactions to coniferyl benzoate and benzyl alcohol. Most of the reactions to eugenol and isoeugenol had less to do with BP itself than with a primary sensitization to fragrances. Although resorcin monobenzoate (RMB) has up to now not been detected in BP, 16 patients reacted distinctly to this compound. Eleven were strong smokers; the remaining ones had contact with plastic materials that have been reported to contain RMB. RMB is used frequently as an antioxidant in synthetic material. When these patients stopped smoking, the skin lesions cleared. However, consumption of sweets caused recurrences.

CONCLUSION

The evaluation of reactions to single constituents of BP by testing with the special BP series facilitates understanding how sensitization may be acquired. The allergen may prove to be BP itself or 1 or more of its constituents. Testing for the constituents of this series may provide patients with a more specific allergen diagnosis and may facilitate improved therapy. BP may function as an important indicator for contact allergy to RMB.

Contact allergy to Disperse Blue 106 and Disperse Blue 124 in German and Austrian patients, 1995 to 1999

Between 1995 and 1999, 1986 patients were tested in the 31 participating centres of the Information Network of Departments of Dermatology (IVDK), all of them members of the German Contact Dermatitis Research Group, with a textile dyes series containing Disperse Blue (DB) 106 and 124, and since 1997 also with a mix of both. 86 patients (4.3%) reacted positively to DB 106 and/or DB 124; with good concordance between the 2 allergens (Cohen's weighted kappa 0.72), and the single allergens and the mix (kappa=0.75 in both cases), which had been tested in parallel in 969 and 975 patients, respectively. In contrast, concordance between DB 106/124 and p-phenylenediamine and p-aminoazobenzene, respectively, was poor. Some 70% of positive reactions to DB 106/124 had current clinical relevance. Furthermore, a significant increase in the proportion of DB 106/124-positive patients among those tested was found from 1995 to 1999. Hence, DB 106/124 are important allergens deserving close monitoring. The use of a mix of DB 106 and DB 124 seems justified in view of the close chemical similarity of both compounds. If possible, the presence of the allergen(s) in individual textiles considered causative should be checked by thin layer or column chromatography.

[Contact allergy caused by poison ivy (Toxicodendron spp]

Within 3 days two female patients presented with an eruption featuring erythema, edema, vesicles and bullae. We suspected poison ivy allergy which was subsequently proven by history and positive patch tests. In Germany the risk of specific hypersensitivity to Toxicodendron species is low, since the distribution of such plants is confined to botanical gardens. Other species belonging to the family of Anacardiaceae contain urushiols as well (e.g., mango, cashew) and may cause allergic contact dermatitis.

Allergic contact dermatitis from hydrangea--is it so rare?

8 cases of allergic contact dermatitis from hydrangea seen in Angers, France, during the last 15 years are reported and compared to other cases found in the literature. In this review, allergic contact dermatitis from hydrangeas appears to be an occupational dermatosis among nursery workers, presenting as an eczema involving the hands and especially the first 3 fingers, with chronic features of fissuring and scaling and with a chronic course. Differential diagnosis from irritant contact dermatitis may be difficult. Patch tests with the stem as well as the leaf of hydrangeas gave strong positive reactions in all patients, and hydrangenol, the allergen of hydrangea, when tested, always also gave a positive reaction. Sensitization seems to occur after close and prolonged contact with the plant, which could explain the relative frequency in Angers because it provides almost 90% of hydrangea seedling production in France.

Allergenic sesquiterpene lactones from Eupatorium cannabinum L. and Kaunia rufescens (Lund ex de Candolle)

From Eupatorium cannabinum L., a hitherto unknown alpha-methylene-gamma-butyrolactone, 3 beta-peroxyeucannabinolide, was isolated. This compound and eupatoriopicrin from the same plant showed a weak sensitizing capacity in guinea pigs. 2-oxoludartin and dehydroleucodin, isolated from Kaunia rufescens (syn. Eupatorium rufescens), were strong sensitizers in the same sensitizarian procedure.

Sensitizing capacity of azole derivatives: Part III. Investigations with anthelmintics, antimycotics, fungicides, antithyroid compounds, and proton pump inhibitors

BACKGROUND

More than hundred azole derivatives are used today for different purposes. The majority possess antimycotic, antibacterial, anthelmintic, and antiprotozoal properties. They are used as agricultural fungicides; topical antimycotics, and, for example, in antidandruff cosmetics. More recently the antithyroid and antiulcerative activity of certain imimidazoles and benzimidazoles also has been proven, which led to the introduction of proton pump inhibitors and antithyroid drugs to the market.

OBJECTIVE

Case reports from the literature and experimental studies suggest that some of the azole derivatives possess a distinct sensitizing potency. Occupational exposure either in the pharmaceutical manufacture or in the pesticide's application by farmers caused allergic contact dermatitis (ACD). However, experimental studies in guinea pigs to determine their sensitizing capacity have been performed only sporadically.

METHOD

Guinea pigs were sensitized by a modified Freund's complete adjuvant (FCA) method, with 35 azoles used as agricultural fungicides, proton pump inhibitors, antimycotics, antithyroid agents, antiprotozoals, antimicrobials, anthelmintics, and wood preservatives.

RESULTS

Four azoles exhibited a strong sensitizing capacity, 3 a moderate, and 11 a weak sensitizing capacity. Seventeen derivatives remained negative. Among the strong sensitizers were the 3 proton pump inhibitors omeprazole, pantoprazole, and rabeprazole, as well as the antithyroid drug carbimazole. The latter displayed the highest sensitizing power (mean response = 2.50) of all 62 azole derivatives investigated in the present and the 2 previous experimental studies.

CONCLUSION

As long as the strong sensitizing azoles are used only systemically the risk of acquiring contact hypersensitivity is low. However, if the idea should arise to use them topically, for example in ointments, tinctures, or lotions against fungal infections, skin problems will probably be observed abundantly.

Degradation products of monoterpenes are the sensitizing agents in tea tree oil

BACKGROUND

Patients using tea tree oil (TTO) topically may become sensitized to this natural remedy. More than 30 cases have been documented in the literature since 1991.

OBJECTIVE

Freshly distilled, as well as oxidized TTO, some fractions, and single constituents were used for experimental sensitization in guinea pigs. TTO was stored on a window sill to study the influence of light, oxygen, and warmth. The oxidized oil and different fractions were devoted to experimental sensitization in guinea pigs to determine their sensitizing potency. Fifteen constituents were patch tested in TTO-sensitive patients to find how many may play a role as contact allergens.

METHODS

Guinea pigs were sensitized by a modified FCA-method (Freund's complete adjuvant) with freshly distilled TTO, oxidized TTO, the monoterpene and sesquiterpene fraction, and 1, 8-cineole. TTO-sensitive patients were tested with 15 typical constituents and degradation products. Gas chromatographic analysis was used to detect degradation products of the deteriorated TTO.

RESULTS

Fresh TTO was revealed to be a very weak sensitizing material whereas oxidized TTO was 3 times stronger. The monoterpene fraction showed to be a stronger sensitizer than the sesquiterpene fraction. All 11 patients reacted mostly with a ++-plus or even a -plus reaction to alpha-terpinene, terpinolene and ascaridol. alpha-Phellandrene became positive in four patients, myrcene in only two. Gas chromatographic analyses showed that the formation of peroxides increased within 4 days from less than 50 to more than 500 ppm. Peroxides, epoxides and endoperoxides were formed. Deterioration products of alpha-terpinene were found to be mainly p-cymene, ascaridol, isoascaridol, a ketoperoxide, and colorless crystals that likely were 1,2,4-trihydroxy menthane. The p-cymene content increased dramatically from 2% to 11.5%. alpha- and gamma-terpinene, as well as terpinolene, were reduced to one half of their former concentration. Ascaridol and isoascaridol have never before been found in TTO.

CONCLUSION

Tea tree oil kept in open and closed bottles or other containers undergoes photooxidation within a few days to several months, leading to the creation of degradation products that are moderate to strong sensitizers. Peroxides, epoxides and endoperoxides, like ascaridol and 1,2,4-trihydroxy menthane, are formed. These must be considered responsible for the development of allergic contact dermatitis seen in individuals treating themselves with the oil. A test series with 15 characteristic constituents is recommended for patch testing.

Garlic-related dermatoses: case report and review of the literature

BACKGROUND

Garlic is widely appreciated as a spice and as a vegetable as well as an over-the-counter phytotherapeutic. From a dermato-allergological standpoint, several garlic-related adverse reactions have to be distinguished.

OBJECTIVE

The corresponding literature is reviewed briefly, with regard to our present observation of a cook, who contracted garlic-induced contact dermatitis being analyzed for its complex pathomechanism.

METHODS

The patient showed a positive type-IV patch test reaction for diallyl disulfide, a low molecular weight garlic ingredient; and strong, non-irritant reactions after 20 min and 24 hrs in the scratch chamber test with fresh total garlic.

RESULTS

Thus, in this case of an occupational dermatosis, protein contact dermatitis had to be considered, as well as allergic type-IV contact dermatitis as a co-existing pathomechanism.

CONCLUSIONS

The spectrum of garlic-related adverse reactions comprises irritant contact dermatitis, with the rare variant of zosteriform dermatitis; induction of pemphigus, allergic asthma and rhinitis; contact urticaria; protein contact dermatitis; allergic contact dermatitis, including the hematogenic variant; as well as combinations thereof, as evidenced by our present case observation.

The sensitizing capacity of ginkgolic acids in guinea pigs

BACKGROUND

Ginkgo biloba possesses fruits that have caused numerous cases of allergic contact dermatitis. Low amounts of the ginkgolic acids occur in the leaves as well.

OBJECTIVE

Leaf extracts are used to treat cerebrovascular and peripheral vascular disorders. The question arises whether skin hypersensitivity reactions may be adverse effects because the pharmaceutical preparations contain low amounts of ginkgolic acids.

METHODS

Guinea pigs were sensitized experimentally with pure ginkgolic acids as well as with leaf extracts containing approximately 1,000 ppm of ginkgolic acids.

RESULTS

The guinea pigs could be sensitized successfully with the pure ginkgolic acids. The animals could not be sensitized with the leaf extract.

CONCLUSION

Leaf extracts of Ginkgo biloba taken orally or given by infusion to treat diffuse cerebral disturbances can be considered safe, even when they might contain up to 1,000 ppm of the sensitizing ginkgolic acids.

Thespesia populnea dermatitis

BACKGROUND

The allergenic properties of milo wood have not been known before now.

OBJECTIVE

We investigated the wood and elucidated the structure of its main sensitizer.

METHODS

A bowl turner suffered from allergic contact dermatitis over years. Wood shavings were extracted, and the constituents were isolated, purified, and identified. The sensitizing capacity of the main compound was determined experimentally in guinea pigs.

RESULTS

Initially, patch tests with sawdust suspensions and the isolated main constituent were positive. During the course of the study, however, the patient developed tolerance. The main component of milo wood was identified as a new mansonone: 7-hydroxy-2,3,5,6-tetrahydro-3,6, 9-trimethylnaphtho [1,8 bc] pyran-4,8-dione. In the sensitizing experiments, it showed to be a moderate sensitizer.

CONCLUSION

Extensive and long-lasting exposure to certain sensitizers may cause the phenomenon of hardening as has been shown in the wood working industry.

Allergic contact dermatitis from a wooden necklace

A 36-year-old female kitchenworker twice developed eczematous lesions corresponding exactly to the area around her neck where she had worn a wooden necklace. Contact dermatitis lasted longer than 1 week. The necklace consisted of 42 brown wooden beads and 63 other wooden parts, 0.5 to 3 cm diameter. Most parts could be identified as Cocobolo wood, Brazilian and East Indian rosewood, and teak. Patch tests with the pure constituents gave +3-reactions to three dalbergions and obtusaquinone, which are known to be the sensitizers of Cocobolo and the above-mentioned rosewoods. Because of these test results, the identification of the species by eye examination could be corroborated. Further detailed questioning revealed that the patient had played a recorder, probably made from Cocobolo (Dalbergia retusa), when a child, to which she unknowingly became allergic.

Occupational allergic contact dermatitis from carnosol, a naturally-occurring compound present in rosemary

A 56-year-old man, working in a food processing factory, developed contact dermatitis of his hands, forearms, and face after the introduction of a new herb extract (Rosmanox) made from the leaves of rosemary (Rosmarinus officinalis). He reacted to carnosol, the main constituent of Rosmanox. 226 controls were negative. To our knowledge, this is the 1st reported case of contact dermatitis from carnosol.

A 6-year experience with compositae mix

A Compositae plant mixture consisting of short ether extracts of arnica, German chamomile, feverfew, tansy, and yarrow has been included in the standard series for several years (1985 to 1990) to study the frequency of allergic reactions to Compositae (Asteraceae) species. One hundred eighteen of 3,851 tested individuals gave a positive response (3.1%). Further tests with the single species of the mixture and some additionally tested extracts of chrysanthemums and laurel oil (bay leaf; Lauraceae) revealed a high percentage of reactions to feverfew (70.1%) and lower responses to chrysanthemums (63.6%), tansy (60.8%), chamomile (56.5%), arnica (51.8%), yarrow (51.8%), and the cross-reacting laurel oil (50.5%). Ten of 85 reacted to arnica alone. The results show that it is important to test Compositae extracts in patients with allergic contact dermatitis because these contain (in contrast to a mixture of pure sesquiterpene lactones) other constituents (e.g., polyacetylenes, thiophenes) that may also contribute to the acquired hypersensitivity. Unrevealed sources of hand and face eczema (including airborne contact dermatitis) might be diagnosed more frequently.

1,2,3-Trithiane-5-carboxylic acid, a first contact allergen from Asparagus officinalis (Liliaceae)

BACKGROUND

Although hundreds of cases of allergic contact dermatitis caused by asparagus have been described in the literature, the responsible allergens are still unknown.

OBJECTIVE

Fresh asparagus shoots were purchased in early April. Juice and ether extracts were prepared and stored in a deep freezer until chemical investigations and patch tests could be performed. Known constituents were obtained from investigators who have isolated asparagus components.

METHODS

Asparagus-sensitive patients were patch tested with the juice or fresh parts of asparagus and four constituents. One of the compounds was synthesized to get greater amounts for experimental sensitization in guinea pigs.

RESULTS

All patients gave positive results with the fresh asparagus and 1,2,3-trithiane-5-carboxylic acid, one of its constituents. Experimental sensitization showed that asparagus has a weak to moderate sensitizing capacity. 1,2,3-Trithiane-5-carboxylic acid showed a similar sensitizing power in the experiments. 1,2,3-Trithiane-5-carboxylic acid is a plant growth inhibitor occurring in asparagus mainly in the early phase of the season.

CONCLUSION

For the first time, a sulfur-containing growth inhibitor could be determined as a contact sensitizer in an edible plant. A second sensitizing constituent was detected, of which the structure could not yet be elucidated completely.

The allergens of nail polish. (I). Allergenic constituents of common nail polish and toluenesulfonamide-formaldehyde resin (TS-F-R)

Nail polish that has completely dried on the fingernails contains water-soluble components that attain the skin during extensive but transient contact. This was proven by water extraction of thin layers of nail polish that had been painted onto glass plates and allowed to dry for 3 days. Comparing the isolated fractions and compounds with known nail polish ingredients revealed that the water-soluble substances are para- and ortho-toluenesulfonamide, dibutyl phthalate and 3 constituents of toluenesulfonamide-formaldehyde resin (TS-F-R), which is the basic material of almost all nail polishes sold worldwide. 12 female patients with proven nail polish allergy were patch tested with 21 nail polish components, including those isolated. Only 2 fractions were positive. These contained a monomer and a dimer created during condensation of TS-F-R. Their structures were elucidated. The 3rd compound, a trimer, remained negative, except in 1 case.

Butenylbithiophene, alpha-terthienyl and hydroxytremetone as contact allergens in cultivars of marigold (Tagetes sp.)

Ornamental cultivars of Tagetes sp., commonly named marigold, are one of the presently most popular pot and garden plants. Sensitizing experiments in guinea pigs with short ether extracts and isolated compounds revealed the presence of 3 constituents that must be considered as contact allergens. They were identified as 5-(3-buten-1-ynyl)-2,2'-bithiophene, alpha-terthienyl and hydroxytremetone. In sensitized animals, butenylbithiophene showed moderate to strong sensitizing potency, while alpha-terthienyl was less strong and hydroxytremetone weak. The results demonstrate, for the first time, that at least some of the thiophenes abundantly occurring in many species of the Compositae family possess not only phototoxic activity but also sensitizing properties.

Structure-activity relationships in allergic contact dermatitis (I). Studies on the influence of side-chain length with derivatives of primin

Primin (2-methoxy-6-pentyl-1,4-benzoquinone) is a naturally-occurring strong sensitizer from Primula obconica (Primulacease). To determine the effect of side-chain length on sensitizing potency, 15 analogues with linear side chains from C1 to C15 and 4 C6-analogues with branched side chains were prepared synthetically and devoted to experimental sensitization in guinea pigs. The results showed an increase of the sensitizing capacity with increasing length of the alkyl side chain from C1 to C10, reaching a maximum at C11 and C12. On further elongation, the sensitizing potency decreased beyond C13, reaching values which finally were as low as those of the C1 and C3 derivatives. The results mirror findings which formerly have been obtained with other non-quinonoid compounds like catechols, phenols, hydroquinones and gallates. In the plant kingdom, compounds approximating an "ideal allergen" consisting of a quinonoid ring with a 10 or 11 carbon-membered side chain have been identified only once: 2,3-dimethoxy-geranyl-1,4-benzoquinone, a remarkably strong sensitizer found in Wigandia caracasana (Hydrophyllaceae).

Allergic contact dermatitis from purified eosin

We report on a patient, seen in 1993, who developed sensitization to eosin from topical preparations. The patient had a positive patch test reaction to pure tetrabromofluorescein but not to its impurities separated by thin-layer chromatography. Our findings suggest that the allergen was eosin itself.