Electronic Textbook of Dermatology

1. Pathak MA. Phytophotodermatitis. Clin Dermatol 1986; 4:102-121.

 2. Hansen M. Identification of plants. Semin Dermatol 1996; 15:122-123.

 3. Dauncey EA, Leon CJ. Plant identification for medical professionals: A computerized solution. Semin Dermatol 1996; 15:124-130.

 4. Radford AE. Fundamentals of plant systematics. New York: Haper and Row, 1986.

 5. Kaufman PB, Carlson TF, Dayanandan P. Plants: Their biology and significance. New York: Harper and Row, 1989.

 6. Encarta 96 Encyclopedia. Microsoft Corporation. 1995;

 7. Porter CL. Taxonomy of flowering plants. San Francisco: W.H. Freeman and Company, 1959.

 8. Anonymous International code of botanical nomenclature (Tokyo Code). 15th ed. Konigstein, Germany: Koeltz Scientific Books, 1994.

 9. Mabberley DJ. The plant-book. First ed. Cambridge: Cambridge University Press, 1987.

 10. Brizicky GK. Taxonomic and nomenclatural notes on the genus Rhus (Anacardiaceae). J Arnold Arbor 1963; 44:60-80.

 11. Gillis WT. The systematics and ecology of poison-ivy and the poison-oaks (Toxicodendron, Anacardiaceae). Rhodora 1971; 73:72-159+.

 12. Pesman MW. Meet the Natives: The amateur's field guide to Rocky Mountain Wildflowers, Trees & Shrubs. 9th ed. Denver: Denver Botanic Gardens, 1992.

 13. Kulze A, Greaves M. Contact urticaria caused by stinging nettles. Br J Dermatol 1988; 119:269-270.

 14. Lahti A. Contact urticaria to plants. Clin Dermatol 1986; 4:127-136.

 15. Lovell CR. Plants and the skin. First ed. Oxford: Blackwell Scientific Publications, 1993.

 16. Southcott RV, Haegi LAR. Plant hair dermatitis. Med J Aust 1992; 156:623-632.

 Principal Poisons Centre for South Australia, SA.

OBJECTIVE: To survey the ill effects of plant hairs on humans in Australia, incorporating new records.
DESIGN: Retrospective analysis of new records, in some cases confirmed and supplemented by experimental skin contacts, along with a general survey of relevant literature.
METHODS: Reports of accidental injuries submitted to the authors, through either medical or other sources, and to the Botanic Gardens of Adelaide and State Herbarium of South Australia, were studied and compared with existing literature; in some cases the effects were confirmed experimentally.
RESULTS: A general survey of plant hair dermatitis in Australia is offered. Most species included have been referred to in the scattered earlier literature, but a few plants not previously recorded as irritating are included, notably Apalochlamys spectabilis, Wisteria sinensis and Grevillea species. Attention is also called to the penetrating and irritating pod spines of Brachychiton spp. (kurrajongs and relatives) and Lagunaria patersonii (Norfolk Island hibiscus or pyramid tree), which are often planted as ornamental street trees. Generally those most likely to receive these injuries are gardeners and children.  

17. Hardin JW, Arena JM. Human poisoning from native and cultivated plants. Durham, NC: Duke University Press, 1969.

 18. Oliver F, Amon EU, Breathnach A, Francis DM, Sarathchandra P, Black AK, et al. Contact urticaria due to the common stinging nettle (Urtica dioica) - histological, ultrastructural, and pharmacological studies. Clin Exp Dermatol 1991; 16:1-7.  

Institute of Dermatology, St Thomas's Hospital, London, UK.

 A frequent cause of contact urticaria is skin exposure to the common stinging nettle (Urtica dioica). The urticaria is accompanied by a stinging sensation lasting longer than 12 h. Little is known of the cellular and molecular mechanism of stinging-nettle urticaria. After preliminary pharmacological analysis of pro-inflammatory activity in nettle stings, the cellular response of mononuclear cells, polymorphonuclear cells and mast cells was examined in six people 5 min and 12 h after nettle contact. Only mast cell numbers were significantly increased at 12 h. Ultrastructurally, some mast cells showed evidence of degranulation at 5 min and 12 h. At 12 h mast cells were closely associated with dermal dendritic cells and lymphocytes suggesting a functional unit. The mean histamine and serotonin contents of a nettle hair were found to be 6.1 ng and 33.25 pg, respectively. Nettle-sting extracts did not demonstrate histamine release from dispersed rat mast cells in vitro. These results suggest that part of the immediate reaction to nettle stings is due to histamine introduced by the nettle. However, the persistence of the stinging sensation might suggest the presence of substances in nettle fluid directly toxic to nerves or capable of secondary release of other mediators.  

19. Stoner JG, Rasmussen JE. Plant dermatitis. J Am Acad Dermatol 1983; 9:1-15.

 This review summarizes the major categories of plant dermatitis: (1) mechanical injury, (2) pharmacologic injury, (3) primary irritant phytodermatitis, (4) allergic phytodermatitis, (5) pseudophytodermatitis, (6) phytophotodermatitis, and (7) pseudophytophotodermatitis. Representative species from this classification are considered. Field characteristics, dermatitis produced, chemical constituents, and diagnosis are discussed.  

20. Juckett G. Plant dermatitis: Possible culprits go far beyond poison ivy. Postgrad Med 1996; 100:159-171.

Given the variety of existing plant species in the environment, it is remarkable that people have adjusted as well as they have to the many plants that can cause uncomfortable skin reactions. With a basic understanding of the types of reaction and the common plants that cause each type, physicians can help patients discover the source of the dermatitis and thus prevent reexposure. In immediate contact dermatitis, welts form rapidly after patients brush against an offending plant, but the urticarial rash is short-lived. In irritant contact dermatitis, the skin is traumatized mechanically (eg, with cactus spines) or chemically (eg, with capsaicin from hot peppers), producing a more persistent skin reaction. Phytophotodermatitis occurs when the skin is exposed to sunlight after contact with an offending plant; reactions are erythema, pruritus, vesiculation, and subsequent hyperpigmentation. Allergic contact dermatitis, typified by the rash of poison ivy, is a cell-mediated immune response that occurs in previously sensitized persons. Erythema, vesiculation, and pruritus, which usually heal without causing pigmentary changes, may last for several weeks.  

21. Edwards EK, Jr., Edwards EK, Sr. Immediate and delayed hypersensitivity to the nettle plant. Contact Derm 1992; 27:264-265.

 22. Epstein WL. Plant-induced dermatitis. Ann Emerg Med 1987; 16:950-955.

 Patients with plant-induced dermatitis frequently present to the emergency department. The range of responses varies from irritant to allergic to photo or granulomatous. To a certain extent the clinical presentations will vary; it is important to determine causation because appropriate emergency therapy treatment also will vary. This review considers the most common forms of plant dermatitis and emphasizes advances in the understanding of pathomechanisms and recommended therapy for each type.

23. Lovell CR. Current topics in plant dermatitis. Semin Dermatol 1996; 15:113-121.  

24. Lindsey D, Lindsey WE. Cactus spine injuries. Am J Emerg Med 1988; 6:362-369.

Cactus spines produce injuries whose clinical significance is loosely in inverse proportion to the dimensions of the spine. Long and medium spines of saguaro and barrel cacti seldom result in embedded fragments, but when they do they are difficult to locate and remove. Other medium spines, those of prickly pear and cholla, are a nuisance but they can be removed readily by traction, as can the smaller spines (glochids) of the prickly pear. The very small spines (also glochids) of the polka dot or bunny's ear cactus (Opuntia microdasys) and the beavertail cactus (Opuntia basilaris) offer the most frustrating problem of all, but can be peeled off with a dried film of a professional facial gel.  

25. Stoner JG. Miscellaneous dermatitis-inducing plants. Clin Dermatol 1986; 4:94-101.  

26. Mitchell J, Rook A. Botanical dermatology. Vancouver: Greengrass, 1979.

 27. Martinez TT, Jerome M, Barry RC, Jaeger R, Xander JG. Removal of cactus spines from the skin: A comparative evaluation of several methods. Am J Dis Child 1987; 141:1291-1292.

 The removal of very fine cactus spines from the skin is particularly distressing for the pediatric patient. We describe two typical patients and a study in experimental animals comparing the effectiveness of several previously described methods for removal. The most effective method involved using tweezers to remove clumps of spines followed by a thin layer of glue covered with gauze, which was allowed to dry and then peeled off to remove individual spines. Attempts to use adhesive tape or a thin layer of a commercial facial mask to aid in removal of the spines produced more retention and inflammation three days after removal than no treatment.  

28. Taussig SJ, Batkin S. Bromelain, the enzyme complex of pineaple (Ananas comosus) and its clinical application, an update. J Ethnopharmacol 1988; 22:191-203.

 After a short description of the uses of pineapple as folk medicine by the natives of the tropics, the more important new pharmaceutical applications of bromelain, reported between 1975 and 1978, are presented. Although the exact chemical structure of all active components of bromelain is not fully determined, this substance has shown distinct pharmacological promise. Its properties include: (1) interference with growth of malignant cells; (2) inhibition of platelet aggregation; (3) fibrinolytic activity; (4) anti-inflammatory action; (5) skin debridement properties. These biological functions of bromelain, a non-toxic compound, have therapeutic values in modulating: (a) tumor growth; (b) blood coagulation; (c) inflammatory changes; (d) debridement of third degree burns; (e) enhancement of absorption of drugs. The mechanism of action of bromelain affecting these varied biological effects relates in part to its modulation of the arachidonate cascade.

29. Webster GL. Irritant plants in the spurge family (Euphorbiaceae). Clin Dermatol 1986; 4:36-45.

30. Gunther PT. The Greek herbal of Dioscorides. New York: Hafner, 1909.  

31. Agricultural research service of the United States Department of Agriculture. Common weeds of the United States. First ed. New York: Dover Publications, Inc. 1971.

 32. Turner NJ. Counter-irritant and other medicinal uses of plants in the Ranunculaceae by native peoples in British Columbia and neighboring areas. J Ethnopharmacol 1984; 11:181-201.

 At least 20 species in Ranunculaceae, the buttercup family, are reported as having been used medicinally by 19 different groups of native peoples in British Columbia and adjacent areas. These species are known to contain the skin-irritating, blister-causing compound, protoanemonin, in their fresh state. Protoanemonin is almost certainly the active principle involved in many of these medicinal applications. A majority involved the use of the plants as external poultices for boils, cuts, abrasions and other skin sores. Other disorders having a high frequency of treatment with ranunculaceous species include: muscular aches, colds and other respiratory ailments, and general, unspecified illness. Native groups in other parts of North America also used many ranunculaceous species as poultices, and for colds, headaches and many other ailments. A number were used for stimulation and "revival" of unconscious persons. It is suggested that the protoanemonin contained in these plants may have, through several different mechanisms, positively influenced the healing process physiologically and not just psychologically. If future research confirms this, these protoanemonin containing plants may have potential in certain treatments in modern medicine.

33. Burnett JW. Capsicum pepper dermatitits. Cutis 1989; 534

34. Williams SR, Clark RF, Dunford JV. Contact dermatitis associated with capsaicin: Hunan hand syndrome. Ann Emerg Med 1995; 25:713-715.  

"Hunan hand" is a contact dermatitis resulting from the direct handling of chili peppers containing capsaicin. Capsaicin also is found in an over-the-counter topical agent for treatment of postherpetic neuralgia, diabetic neuropathy, and arthritis. We present the case of a patient with capsaicin-induced dermatitis and discuss the pathophysiology, therapy, and current uses of capsaicin.  

35. Jones LA, Tandberg D, Troutman WG. Household treatment for "chile burns" of the hands. Clin Toxicol 1987; 25:483-491.

 In New Mexico, chile peppers (Capsicum annum) are prepared by roasting and manually removing the skin from the fruit. Peeling is often done barehanded and may cause prolonged burning pain, irritation, and erythema but not vesication. In a survey of elderly Hispanic women, treatment with oils or cool tap water were frequently used home remedies. Twenty female subjects immersed their hands in a standardized slurry of green chile for 40 minutes, afterwards one hand was placed in cool tap water and the other in vegetable oil for a total of 75 minutes. Pain was scored using a visual analog scale while the hands were immersed in the chile slurry, test baths, and after drying. The difference in pain score was calculated for each subject. Analysis was by pooled regression. Cool tap water immersion initially provided more relief while vegetable oil provided better long-term relief from the pain of "chile burns".

 36. Tominack RL, Spyker DA. Capsicum and capsaicin - a review : case report of the use of hot peppers in child abuse. Clin Toxicol 1987; 25:591-601.

 Capsaicin, the active principle of hot peppers of the genus Capsicum, exhibits broad bioactivity. It targets neuronal structures which contain substance P, clinically seen as gastrointestinal and dermatologic irritation, bronchospasm and fibrinolysis. As a research tool, capsaicin profoundly alters neurologic anatomy and function. We review the toxicity of capsaicin and comment briefly on the use of hot peppers in child abuse.

 37. Gonzalez E, Gonzalez S. Drug photosensitivity, idi0pathic photodermatoses, and sunscreens. J Am Acad Dermatol 1996; 35:871-885.

 Photosensitization may be defined as a process in which a reaction to normally innocuous radiation is induced by the introduction of a specific radiation-absorbing substance (the photosensitizer) that causes another component (the substrate) to be changed by the radiation. This review focuses on photosensitization produced by exogenous chemicals. Idiopathic photodermatoses, including polymorphous light eruption and its variants, solar urticaria and chronic actinic dermatitis, are also discussed. Clinical recognition patterns of the photodermatoses are stressed as well as several diagnostic procedures available for confirmation of the condition. Finally, descriptions, therapeutic uses, and adverse reactions of sunscreens are provided.

 38. Pathak MA, Fitzpatrick TB. The evolution of photochemotherapy with psoralens and UVA (PUVA): 2000 BC to 1992 AD. J Photochem Phtobiol B:Biol 1992; 14:3-22.

 The therapeutic uses of naturally occurring psoralens in modern-day medicine (8-methoxypsoralen (8-MOP), 5-methoxypsoralen (5-MOP), 4,5',8-trimethylpsoralen, and a few other synthetic psoralens) have evolved through five stages of development. (1) In the historical period (2000 BC to 1930 AD), the pigment-stimulating properties of naturally occurring plants containing psoralens were described anecdotally. (2) The second period (1930-1960) dealing with the chemistry of psoralens involved extraction, identification of their structure, synthesis, and the relationship between chemical structure and their photoreactivity and pigment-stimulating properties. The treatment of vitiligo with oral and topical 8-MOP became popular. (3) In the third period (1960-1974), we witnessed a new beginning and the growth of basic science studies and clinical investigations into various biological properties of psoralens including action spectrum studies, mutagenesis and carcinogenesis studies, in vitro and in vivo photoreactivity studies of various psoralens with DNA, RNA, proteins, and pharmacological and toxicological studies in vitiligo patients undergoing long-term therapy for repigmentation. (4) The fourth period (1974-1988) is recognized as the period of photochemotherapy and the development of the science of photomedicine which established the therapeutic effectiveness of psoralens in combination with newly developed UV irradiation systems that emitted high-intensity UVA radiation in the treatment of severe psoriasis, mycosis fungoides, and over 16 other skin diseases. The effectiveness of PUVA (psoralen + UVA) was confirmed by well controlled clinical trials in thousands of patients, both in the USA and in European countries. Combination therapy with oral retinoids and PUVA contributed to greater effectiveness and long-term safety of psoralen photochemotherapy. (5) In the fifth period (1989 and beyond), psoralens are now emerging as photochemoprotective agents against non-melanoma skin cancers and as immunologic modifiers in the management of certain patients with disorders of circulating T-cells using new techniques of photopheresis. In the final analysis, perhaps the application of pharmacological and therapeutic concepts and principles of using psoralens in combination with UVA has contributed to the development of a new science of photomedicine in which the interaction between basic scientists, photobiologists, and physicians has produced both basic and new clinical knowledge for the care and control of human suffering.

 39. White JC. Notes on dermatitis venenata. Boston Med Surg J 1897; 136:177-179.

 40. Stowers JJ. Dermatological society of Great Britain and Ireland. Report of the annual meeting. Br J Dermatol Syphilol 1897; 9:275-285.

 41. Freund E. Uber bisher noch nicht beschriebene kunstliche Hautverfarbungen. Dermatol Wochenschrift 1916; 63:931-933.

 42. Oppenheim M. Dermatite bulleuse striee consecutive aux bains de soleil dans les pres (dermatitis bullosa striata pratensis). Ann Dermatol Syphiligr 1932; 3:1-7.

 43. Kuske H. Experimentelle untersuchungen zur photosensibilisierung der haut durch pflanzliche wirkstoffe. I. Lichtsensibilisierung durch furocoumarine als ursache verschiedener phytogener dermatosen. Arch Derm Syph 1938; 178:112-123.

 44. Jensen T, Hansen KG. Active spectral range for phytogenic photodermatosis produced by Pastinaca sativa. Arch Derm Syph 1939; 40:566-577.

 45. Klaber R. Phytophotodermatitis. Br J Dermatol 1942; 54:193-211.

 46. Kavli G, Volden G. Phytophotodermatitis. Photodermatol 1984; 1:65-75.

 Several plant families contain species liable to cause phytophotodermatitis. They include the Umbelliferae of which Ammi majus has been known for centuries and the Rutacea to which Citrus bergamia belongs. Phototoxic plants are also found in, e.g., the Moraceae, Leguminosae, Rosaceae and Compositae plant families. The photoreactivity of the plants depends on their furocoumarins (psoralens) content. These cause skin damage by phototoxic mechanisms, when activated by longwave ultraviolet radiation (UVA). The results are clinical changes such as erythema, bullae in the skin 24-72 h later, followed by hyperpigmentation. For the strongest phototoxic plants the content of the major phototoxic furocoumarins like bergapten or xanthotoxin have been calculated at approximately 0.5 g/100 g dried plant weight, but it varies between plant parts and also with the age of the plant. Repeated contact may occasionally lead to photocontact allergy.

 47. Hann SK, Park Y, Im S, Byun SW. Angelica-induced phytophotodermatitis. Photodermatol Photoimmunol Photomed 1991; 8:84-85.

 48. Hipkin CR. Phytophotodermatitis, a botanical view. Lancet 1991; 338:892-893.

 49. Ueda A, Manda F, Aoyama K, Ueda T, Obama K, Li Q, et al. Immediate-type allergy related to okra (Hibiscus esculentus Linn) picking and packing. Environ Res 1993; 62:189-199.

 Two workers (cases A and B) engaged in picking and packing okra who had complaints of work-related allergic symptoms showed distinct positive intradermal reactions to two brands of okra extracts only with thresholds of 1 x 10(-8) w/v for Case A and 1 x 10(-6) w/v for Case B. Both also showed positive reactions to okra extracts in the Prausnitz-Kustner test and in the provocative nasal test. The radioallergosorbent test scores to the okra extract were determined to be 2 (defined as clear positive) for Case A and 1 (border line) for Case B. These findings indicated that the allergic conditions of these cases were from an IgE-mediated immediate-type allergy induced by handling okra. To confirm the etiology of the two cases 14 farmers engaged in picking and packing okra were examined. Among them, 8 subjects (57%) showed positive intradermal reactions to okra extracts. A close association between intradermal reactions to okra extracts and complaints of work-related allergic symptoms was seen in these subjects. These results confirm that the okra may be capable of inducing IgE-mediated immediate-type allergy to workers handling okra.  

50. Seligman PJ, Mathias CGT, O'Malley MA, Beier RC, Fehrs LJ, Serrill S, et al. Phytophotodermatitis from celery among grocery store workers. Arch Dermatol 1987; 123:1478-1482.

 We detected 19 cases of phytophotodermatitis during a cross-sectional epidemiological investigation of two Oregon grocery stores that were part of the same supermarket chain. Outdoor sunlight exposure during the workshift and tanning salon use were identified as risk factors; the most severe cutaneous reactions tended to occur among tanning salon users. Although both stores carried the same brands and varieties of produce, all 19 cases occurred among employees of one store, which had held a celery sale coincident with the outbreak, resulting in a quadrupling of the usual volume of celery sold. We found elevated psoralen levels in two of three celery samples obtained from the affected store; cutaneous provocation tests with trimmed surfaces of these celery samples produced phototoxic reactions. Preliminary experiments with one brand of celery have demonstrated psoralen levels as high as 25 micrograms/cm2 of trimmed surface. These observations suggest that clinical phytophotodermatitis among grocery store workers may be caused by healthy celery and results from a complex interaction of exposure variables, including ultraviolet radiation from tanning salon use, frequency of handling celery, celery brand, and sporadic elevation of psoralen content from environmental stresses.

51. Goskowicz MO, Friedlander SF, Eichenfield LF. Endemic "lime" disease: phytophotodermatitis in San Diego county. Pediatrics 1994; 828-830.

 52. Nigg HN, Nordby HE, Beier RC, Dillman A, Macias C, Hansen RC. Phototoxic coumarins in limes. Fd Chem Toxic 1993; 31:331-335.

 Coumarins in the rind and pulp of Persian and Key limes were quantified. In the rind of Persian limes, coumarin concentrations were in the order: limettin > bergapten > isopimpinellin > xanthotoxin > psoralen. In the rind of Key limes, psoralen and xanthotoxin were analytically absent; limettin was 10 times more concentrated than either bergapten or isopimpinellin, which were equal in concentration. Coumarin content in Persian lime pulp was in the order: isopimpinellin > limettin > bergapten > xanthotoxin > psoralen. For Key lime pulp, the concentrations of limettin, isopimpinellin and bergapten were equal; psoralen and xanthotoxin were not detected. Coumarins in lime pulp were 13 to 182 times less concentrated than those in the peel. Based on the amounts and types of coumarins, Persian limes appear to be potentially more phototoxic than Key limes. Although bergapten may be the main component of limes responsible for phytophotodermatitis, dermatological interaction assays with psoralen, bergapten, xanthotoxin and limettin should be conducted.  

53. Coffman K, Boyce WT, Hansen RC. Phytophotodermatitis simulating child abuse. Am J Dis Child 1985; 139:239-240.

 We explored the history in two children who had bizarre, hyperpigmented skin lesions suggestive of child abuse. A final diagnosis of phytophotodermatitis was established. The lesions resulted from inadvertent application of squeezed lime juice to the children's skin by their parents during the routine preparation of drinks, followed by sun exposure, which activated the applied plant psoralens (furocoumarins). Phytophotodermatitis can be induced by a number of plants, and, when unrecognized, may lead to inappropriate investigation of child abuse.

 54. Tunget CL, Turchen SG, Manoguerra AS, Clark RF, Pudoff DE. Sunlight and the plant: a toxic combination: severe phytophotodermatitis from Cneoridium dumosum. Cutis 1994; 54:400-402.

 A severe case of phytophotodermatitis occurred in a patient who had spent several hours walking through an area densely populated with Cneoridium dumosum. This patient's co-worker experienced a similar reaction after undergoing patch testing of an area of skin and exposing it to sunlight. Voluntary patch testing by one of the authors produced a reaction consistent with the other two cases. Approximately twenty other cases were described by a U.S. Fish and Wildlife Service ranger in students who came into contact with the plant during a field trip with him to Baja California, Mexico. Cneoridium dumosum is a common native bush that grows in the chaparral vegetation zone of southern California and Baja California, Mexico. In a search of Poisindex, Medline, Agris International, and Agricola databases, no previous reports of toxic exposures were found.  

55. Elpern DJ, Mitchell JC. Phytophotodermatitis from mokihana fruits (Pelea anisata H. Mann, fam. Rutaceae) in Hawaiian lei. Contact Derm 1984; 10:224-226.

 Bullous dermatitis, which resolved leaving hyperpigmentation and which was clinically consistent with phytophotodermatitis , affected the skin of the neck of 2 individuals who wore Hawaiian leis (as neck garlands ) made of the fruits of Pelea anisata . In a Daniels culture plate system portions of the fruits showed phototoxicity.

 56. Ljunggren B. Severe photoxic burn following celery ingestion. Arch Dermatol 1990; 126:1334-1336.  

 A 65-year-old woman developed a severe, generalized phototoxic reaction following a visit to a suntan parlor. History taking revealed that she had consumed a large quantity of celery root (Apium graveolens) 1 hour earlier. With the use of thin-layer chromatography, methoxsalen (8-methoxypsoralen) and 5-methoxypsoralen were identified in the extract from a similar celery root. The biologic activity of this extract, as evaluated with the semiquantitative Candida albicans inhibition technique, indicated a total psoralen dose of approximately 45 mg. Substantial amounts of psoralen may be absorbed from vegetables, such as celery, and under unusual circumstances, this may constitute a health hazard.

 57. Puig L, deMoragas JM. Enhancement of PUVA phototoxic effects following celery ingestion: cool broth also can burn. Arch Dermatol 1994; 130:809-810.

 58. Kavli G, Volden G, Midelfart K. In vivo and in vitro phototoxicity of different parts of Heracleum laciniatum. Contact Derm 1983; 9:269-273.

 Experimental phytophotodermatitis was produced using homogenates from different parts of Heracleum laciniatum and long-wave ultraviolet light. The homogenates of leaves and flowers produced strong phototoxic reactions, fruit slightly less. Stems were either non-phototoxic or only slightly phototoxic. The roots of young plants did not evoke photosensitivity reactions, whereas the roots of older plants were strongly phototoxic; even roots collected from the frozen ground in December elicited strong reactions. Abdominal and midback skin were more photosensitive than skin of the lateral aspects of the underarms and legs.

 59. Birmingham DJ, Key MM, Tublich GE. Photoxic bullae among celery harvesters. Arch Dermatol 1961; 83:73

 60. Israel E. Outbreak of phototoxic dermatitis from limes - Maryland. MMWR 1985; 34:462

 61. Volden G, Krokan H, Kavli G, Midelfart K. Phototoxic and contact toxic reactions of the exocarp of sweet oranges: a common cause of cheilitis? Contact Derm 1983; 9:201-204.

 Irritant skin reactions were produced within 1 h after application of the exocarp of sweet oranges or alcoholic extracts therefrom. Such reactions faded within 48 h. The exocarp, or extracts thereof, induced phototoxic reactions which were strongest at 72 h after exposure. The phototoxic reactions were only induced in natural blondes and only with some oranges. The in vivo phototoxic reactions were confirmed in vitro, causing a slight but clear photo-inhibition of Candida albicans. Only some oranges inhibited growth.

 62. Zaynoun ST, Aftimos BG, Abi Abi L, Tevekjian KK, Khalidid U, Kurban AK. Ficus carica: isolation and quantification of the photoactive components. Contact Derm 1984; 11:21-25.

 The presence and levels of furocoumarins in several parts of Ficus carica including the milky sap, were investigated. The results show that psoralen and bergapten are the only significant photoactive compounds, and are present in appreciable quantities in the leaf and shoot sap but are not detected in the fruit or its sap. These compounds are more concentrated in the leaf sap compared to the shoot sap. The psoralen levels are several times higher than those of bergapten. Lower concentrations of both compounds are present in autumn compared to spring and summer. These findings suggest that the reaction is induced primarily by psoralen. The response can follow contact with the leaf and shoot sap but not with the fruit sap, and is expected to occur more frequently from exposure to the leaf sap. The higher content of both photoactive compounds in spring and summer is partly responsible for the increased incidence of fig dermatitis during these seasons. Ingestion of the fruit does not cause photosensitization and the absence of photoactive furocoumarins in the fruit and its sap remains unexplained.  

63. Bhutani JK, Rao DS. Photocontact dermatitis caused by Parthenium hysterophorus. Dermatologica 1978; 157:206-209.

 64. Kavli G, Volden G, Raa J. Accidental induction of photocontact allergy to Heracleum laciniatum. Acta DermatoVenereologica 1982; 62:435-438.

 Photocontact allergy to psoralens in Heracleum laciniatum occurred in two persons volunteering for investigations into phototoxicity of plant homogenates and purified psoralens. Photoallergy was noted following the fifth exposure in case 1, and the sixth in case 2. Testing with diluted solutions demonstrated allergy to sphondin, isobergapten and pimpinellin.

65. Ljunggren B. Psoralen photoallergy caused by plant contact. Contact Derm 1977; 3:85-90.

A case of acquired photocontact allergy to furocumarins in plants is reported. Photopatch testing was performed with four psoralens [8-methoxypsoralen (8-MOP), 5-methoxypsoralens (5-MOP), trimethylpsoralen (TMP) and imperatorin (IMP)[. The use of serial dilutions of the test compounds made it possible to differentiate between photoallergic and phototoxic reactions. 8-MOP gave a positive eczematous test reaction down to a concentration of 0.0001%. The reactions to 5-MOP and imp also were positive, while that to TMP was negative. Histopathological examination of a biopsy specimen from a positive test site showed changes consistent with photoallergic contact dermatitis. The multiple reactions could be explained on the basis of multiple sensitization but cross reactions cannot be ruled out.