Toxicodendron dermatitis in the UK

BACKGROUND: We present two cases of Toxicodendron dermatitis, one acquired in the United States but presenting in the United Kingdom (UK), the other a recurrent dermatitis following importation of the plant to the UK. Poison ivy, poison oak and poison sumac are native to North America and belong to the genus Toxicodendron. This group of plants is of interest to the dermatologist because they contain a mixture of potent sensitisers which cause a severe allergic contact dermatitis. CONCLUSIONS: The dermatitis can present to the dermatologist in Europe after an individual has been in contact with the plant whilst visiting an endemic area. The plants have the potential to grow in Europe and it is therefore possible for an individual to be sensitised and subsequently to develop the rash without leaving the continent.     

Is it,or isn't it? Poison ivy look-a-likes

Poison ivy causes more allergic contact dermatitis (ACD) than any other cause. Although physicians rightfully focus on the treatment of the dermatitis, prevention will be aided by recognition of the foreboding plant. Likewise, many other plants can masquerade as poison ivy and cause one to needlessly curtail his or her activities because of fear of a bad reaction. The most common poison ivy pretenders in the United States are discussed, and distinguishing plant characteristics are highlighted.     

Recognizing the Toxicodendrons (poison ivy, poison oak, and poison sumac)

Poison ivy, poison oak, and poison sumac are now classified in the genus Toxicodendron which is readily distinguished from Rhus. In the United States, there are two species of poison oak, Toxicodendron diversilobum (western poison oak) and Toxicodendron toxicarium (eastern poison oak). There are also two species of poison ivy, Toxicodendron rydbergii, a nonclimbing subshrub, and Toxicodendron radicans, which may be either a shrub or a climbing vine. There are nine subspecies of T. radicans, six of which are found in the United States. One species of poison sumac, Toxicodendron vernix, occurs in the United States. Distinguishing features of these plants and characteristics that separate Toxicodendron from Rhus are outlined in the text and illustrated in color plates.     

Black-spot poison ivy dermatitis. An acute irritant contact dermatitis superimposed upon an allergic contact dermatitis

A black spot in the epidermis over a blister of poison ivy dermatitis is an uncommon finding. Four patients with the phenomenon are described. Histologic and histochemical studies were made on biopsy material and the blackish deposit on the skin surface was compared with black deposits in and on leaves of the species of poison ivy. This examination revealed a yellow, amorphous substance on the stratum corneum of the lesions and a similar substance in and on leaves of the poison ivy plant, Toxicodendron radicans ssp. negundo. Associated with the pigmentary deposits there were distinct changes of acute irritant contact dermatitis superimposed upon allergic contact dermatitis. Our findings support the view that the black material is the oleoresin of the plant, and that this substance behaves both as an irritant and an allergen.     

Smodingium allergenic Anacardiaceae in South Africa

The first case reports of genuine poison ivy dermatitis in South Africa appeared in 1959.¹ Eight patients were seen who had developed the rash following contact with a creeper in a hedge in Olifantsfontein near Pretoria. The creeper was identified as Toxicodendron radicans and had presumably been imported from North America, since it is not indigenous to South Africa. Similar cases have been seen since then in Johannesburg.²In 1963, seven patients from Pretoria and Johannesburg with a unique dermatitis of “poison-ivy type” were reported.³ These patients had not been exposed to imported American poison ivy but had reacted to an indigenous plant identified as Smodingium argutum, known by various common names, including tovana and rainbow leaf. It transpired that Smodingium dermatitis had been recognized by tribal blacks, foresters, botanists, horticulturists, and amateur gardeners for many years before the medical profession became aware of it. In subsequent years, this type of dermatitis became widely recognized and many more cases were seen, leading to further case studies² and investigations.^4,5In 1971. four South African patients were reported with a similar type of “poison ivy” dermatitis who had been exposed to the wax tree, Toxicodendron succedanea, an oriental sumac.² It became clear from cross-sensitivity reactions in certain patients that there were antigenic similarities between the oleoresins from S. argutum, T. radicans and T. succedanea, all members of the family Anacardiaceae.² An identical dermatitis is produced by all three plants.     

Exploring the mango-poison ivy connection: the riddle of discriminative plant dermatitis

A relationship between sensitivity to poison oak or poison ivy and mango dermatitis has been suggested by previous publications. The observation that acute allergic contact dermatitis can arise on first exposure to mango in patients who have been sensitized beforehand by contact with other urushiol-containing plants has been documented previously. We report 17 American patients employed in mango picking at a summer camp in Israel, who developed a rash of varying severity. All patients were either in contact with poison ivy/oak in the past or lived in areas where these plants are endemic. None recalled previous contact with mango. In contrast, none of their Israeli companions who had never been exposed to poison ivy/oak developed mango dermatitis. These observations suggest that individuals with known history of poison ivy/oak allergy, or those residing in area where these plants are common, may develop allergic contact dermatitis from mango on first exposure. We hypothesize that previous oral exposure to urushiol in the local Israeli population might establish immune tolerance to these plants.     

Leaves of three, let them be: if it were only that easy!

Humans of all races and skin color are susceptible and uniquely sensitive to poison ivy, oak, and sumac. Contact with the plant oil, urushiol, found not only in the leaves but in the stems and roots, results in an allergic contact dermatitis in 50% to 60% of people. Clinical manifestations, differential diagnosis, complications, and treatments are discussed, with a special emphasis on the pediatric population.     

Black spot poison ivy: A report of 5 cases and a review of the literature.

Black-spot poison ivy dermatitis is a rare manifestation of a common condition. It occurs on exposure to the resins of the plants of the Rhus family also known as Toxicodendron. We describe 5 patients with black deposits on their skin and clothing after contact with poison ivy and review the literature reflecting different aspects of this phenomenon including clinical presentation, histologic findings, and historical background.     

Toxicodendron radicans dermatitis with black lacquer deposit on the skin

Four patients with clinical Toxicodendron dermatitis (poison ivy) presented with dramatic black lacquer-like deposits on several lesions. This black deposit was also observed at sites of injury on poison ivy plants and was reproduced on volunteers by the application of plant sap on the skin. Histologically, the observed material was identified in the stratum corneum. This little-recognized phenomenon has been mentioned in past dermatologic literature.     

Kontaktallergie auf 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.     

Erythema multiforme‐like eruption associated with plant‐induced allergic contact dermatitis in a pediatric patient: A case report

An 11‐year‐old boy presented to the emergency department 5 days after playing in the forest. His initial eruption, consistent with allergic contact dermatitis to poison ivy, progressed into target lesions involving his extremities, palms, upper trunk, and face, consistent with an erythema multiforme‐like eruption. This report details the case and reviews the literature concerning this atypical and potentially underreported complication of plant‐induced allergic contact dermatitis.     

Hyposensitization to poison ivy after working in a cashew nut shell oil processing factory

19 adults were patch tested to urushiol, the allergen in poison ivy/oak, to determine their sensitivity to this allergen after working in a cashew nut shell oil (CNSO) processing plant. The cashew nut tree and poison ivy/oak are in the same botanical family. Anacardiaceae, and they share similar chemicals which cause allergic contact dermatitis. 13 of the 19 workers had a preemployment history of poison ivy sensitivity, with 10 developing CNSO dermatitis. After working in this factory for several months, 9 of the 13 noticed a decreased sensitivity or no sensitivity to poison ivy/oak. When tested to urushiol extract, only 3 reacted positively, 2 minimally. These results imply that hyposensitization to poison ivy/oak occurred in these employees after development of hardening to cashew nut shell oil.     

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.     

Treatment of toxicodendron dermatitis (poison ivy and poison oak)

Toxicodendron dermatitis results from a reaction to an oil soluble oleoresin that is present in many parts of the poison ivy and poison oak plants. Prophylactic measures include avoidance, protective clothing, barrier creams and hyposensitization. Treatments include washing the area immediately with a solvent suitable for lipids and the use of anti-inflammatory agents, especially corticosteroids.     

Dermatitis artefacta induced in a patient by one of her multiple personalities

A young woman suffered for 5 weeks with an inexplicable, severe dermatitis limited to her left arm. During hospitalization it was found that she had multiple personalities, one of whom had been applying the leaves of the poison ivy plant each night to her left arm, using 'his' gloved right hand. The factitial nature of the dermatitis was further documented by the fact that when the 'responsible personality' was cut off from supplies of poison ivy in the hospital, 'he' produced factitious haematomas by trauma to her left hand. Although this appears to be the first report of dermatitis artefacta associated with the multiple personality disorder, it is suggested that psychiatric study of other dermatitis artefacta patients might reveal the presence of unsuspected occult multiple personalities, responsible for skin lesions that patients cannot explain.     

Poison ivy dermatitis

Eruptions caused by poison ivy and related plants are almost always a form of allergic contact dermatitis. Usually they can be readily recognized because of their characteristic streak-or-line-like appearance. They usually clear within one to three weeks unless there is continued exposure to the allergen. Local treatment suffices in mild to moderate cases, but in more severe cases systemic corticosteroids can be added.     

Poison ivy dermatitis

Eruptions caused by poison ivy (see Cover) and related plants are almost always a form of allergic contact dermatitis. Usually they can be readily recognized because of their characteristic streak- or line-like appearance. They usually clear within one to three weeks unless there is continued exposure to the allergen. Local treatment suffices in mild to moderate cases, but in more severe cases systemic corticosteroids can be added.     

Dermatitis from common ivy (Hedera helix L. subsp. helix) in Europe: past,present, and future

Common ivy (Hedera helix subsp. helix) is a well‐known native and ornamental plant in Europe. Reports on contact dermatitis from ivy have regularly appeared since 1899. Recently, it has been suggested that allergic contact dermatitis from the plant may be under‐diagnosed, partly due to lack of commercial patch test allergens. The objective of the article is to present the results of aimed patch testing with the main common ivy allergen, falcarinol, during a 16‐year period and review the newer literature. Consecutive patients tested with falcarinol 0.03% petrolatum from May 1993 to May 2009 were included. Cases published since 1987 were retrieved from the PubMed database. One hundred and twenty‐seven Danish patients were tested with falcarinol and 10 (7.9%) tested positive. Seven were occupationally sensitized. Between 1994 and 2009, 28 new cases of contact dermatitis from ivy were reported, 2 of which were occupational. Only 11 of the 28 patients were tested with pure allergens. Falcarinol is not only widely distributed in the ivy family, but also in the closely related Apiaceae. Sensitization may occur in childhood or in adults pruning ivy plants or handling them in an occupational setting. In view of the ubiquity of falcarinol‐containing plants and the relatively high prevalence of positive reactions in aimed patch testing, falcarinol should be the next plant allergen to be commercially available and included in the plant series worldwide.     

Quantitation and cloning of human urushiol specific peripheral blood T-cells: isolation of urushiol triggered suppressor T-cells

A limiting dilution assay was developed to quantitate urushiol (the antigen of poison ivy; Toxicodendron radicans) specific T cells from peripheral blood of a patient with a history of rhus (poison ivy) dermatitis. It was found that maximal sensitivity with minimal nonspecific proliferation could be produced with the use of 5 U/ml of recombinant IL2 added to the assay on day 6. This donor was found to have a frequency of urushiol specific peripheral blood T cells of (1/2935). Five interleukin 2 (IL2) dependent urushiol specific T-cell clones were generated from the peripheral blood of this patient. These T-cell clones had a CD8+ (T8+) phenotype and proliferated specifically to both extracts of Toxicodendron radicans (poison ivy) leaves and pure urushiol. Pentadecylcatechol was an inferior antigen, only stimulating proliferation of one clone. The ability of all clones to proliferate to pure urushiol, despite their having been induced with leaf extract, suggests that urushiol, or closely related catechols, represent the only allergenic constituents of Toxicodendron radicans. Lymphokine production in response to antigen varied between (0.6-5.0) units/ml of interleukin 2 (IL2) and (1.0-120) units/ml of gamma interferon. Although none of the clones showed significant cytotoxicity against NK targets, three of five lines showed considerable cytotoxicity against concanavalin A treated (lectin approximated) targets. However, cytotoxicity for rhus conjugated autologous targets was not detected. It was found that several of these CD8+ clones could suppress IgG production in the presence of rhus antigen. The isolation of these T-cells from peripheral blood several months after rhus dermatitis suggests that these clones may have a role in down regulating delayed hypersensitivity to urushiol.     

Allergic contact dermatitis to quaternium 15 in a moisturizing lotion

A 56-year-old nurse from a rural area presented with a 12-month history of hand dermatitis. She had previously been patch tested by a local medical practitioner with the thin-layer rapid-use epicutaneous test, which had shown allergies to quaternium 15 and formaldehyde. After testing, she was prescribed methylprednisolone aceponate 1 mg/g cream by the medical practitioner, but was not informed that quaternium 15 is contained in the Microshield moisturizing lotion she was using at work. When her dermatitis persisted, she saw a dermatologist, who advised her to avoid the Microshield moisturizing lotion, and use a waterless hand cleanser on return to work. The diagnoses were firstly allergic contact dermatitis from quaternium 15 in the moisturizing lotion, and secondly irritant contact dermatitis from nursing work. This case highlights both the presence of quaternium 15 in a product commonly used in health-care settings in Australia, and the importance of offering informed, appropriate advice to patients following patch testing.