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Phytophotodermatitis caused by contact with a fig tree (Ficus carica )

  • University of Auckland Medical School, Waikato Clinical Campus, Hamilton, New Zealand

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Two arborists presented acutely with blistering eruptions affecting their forearms, hands, and fingers. The previous day, both men had pruned branches from a large fig tree, Ficus carica, which had sustained damaged during a storm. The following morning, both complained of a burning discomfort which rapidly evolved into erythema and bullae on skin that had been in direct contact with the tree branches. These symptoms gradually resolved over 4 to 6 weeks. Although phytophotodermatitis from Ficus carica has been reported, it is often poorly recognised and there is a need to raise awareness amongst arborists, orchardists, forestry workers, gardeners, and health professionals.
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Vol 120 No 1259 ISSN 1175 8716
NZMJ 10 August 2007, Vol 120 No 1259 Page 1 of 5
Phytophotodermatitis caused by contact with a fig tree
(Ficus carica)
José G B Derraik, Marius Rademaker
Two arborists presented acutely with blistering eruptions affecting their forearms,
hands, and fingers. The previous day, both men had pruned branches from a large fig
tree, Ficus carica, which had sustained damaged during a storm. The following
morning, both complained of a burning discomfort which rapidly evolved into
erythema and bullae on skin that had been in direct contact with the tree branches.
These symptoms gradually resolved over 4 to 6 weeks. Although phytophotodermatitis
from Ficus carica has been reported, it is often poorly recognised and there is a need
to raise awareness amongst arborists, orchardists, forestry workers, gardeners, and
health professionals.
Plant dermatitis (phytodermatitis) is caused by a reaction in the skin following contact
with certain plants or plant parts. They can be irritant such as cactus spine injuries,
urticarial (e.g. from stinging nettles), allergic from plants such as Primula obconica or
Toxicodendron succedaneum, or they can be phytophototoxic in nature.
Phytophotodermatitis is generally a toxic reaction due to direct skin exposure to
certain plants or plant parts, followed by exposure to ultraviolet (UV) light. The most
common plants to cause phytophotodermatitis belong to the Apiaceae (Umbelliferae)
Other plant families that can cause phytophotodermatitis include Rutaceae,
Moraceae, and Fabaceae.
Case report
Two male arborists were cleaning up storm damaged limbs from a large fig tree, Ficus
carica, which was heavily laden with fruit (e.g. Figures 1 and 2). The work took place
in Auckland between 10:30 am and noon, on a dry, relatively clear summer day (80%
relative humidity, temperature 24°C, total UV exposure in 1.5 hours 3.58 mJ).
Both workers were dressed in short-sleeved shirts or singlets. During the removal of
the storm damage, they wrapped their arms (predominantly their right arms) around
the fig tree branches when dragging them to the wood chipper.
Some 9 hours later, the first arborist noted a burning sensation on his right arm, which
he attributed to sunburn. However, over the next 12 hours, the skin on this arm became
swollen, erythematous, and was sore to touch. Within 24 hours of contact with fig tree
parts, bullae appeared on the forearm, wrist, and back of the hand
NZMJ 10 August 2007, Vol 120 No 1259 Page 2 of 5
Figure 1. The fig tree, Ficus carica
(Photo courtesy of Petr Kocna)
Figure 2. The leaves and fruit of
Ficus carica (Photo courtesy of Petr Kocna)
Figure 3. Second arborist’s forearm approximately 36 hours (A), 48 hours (B), 72 hours (C), 12
days (D), and 35 days (E) after contact with Ficus carica tree branches and exposure to sunlight.
(Photos courtesy of Alex White and Gerald Collett)
(A) (B) (C) (D) (E)
Note: In the photos a ‘ring’ can be observed in the wrist region where an armband presumably prevented exposure to
sunlight and the consequent occurrence of phototoxic reaction.
These symptoms on the first arborist persisted for over 2 weeks despite the use of
alternative remedies, including a mixture of lavender oil and Aloe vera gel. As the
acute erythema settled, post-inflammatory pigmentation developed, which slowly
resolved over a month.
The second worker also experienced a burning sensation on his right forearm some 9
hours after working with the fig tree. Blistering of skin was noticed approximately 31
hours after contact with the fig tree (Figure 3), at which point the arborist covered the
blisters and bullae with manuka honey. His condition progressively worsened with
swelling and formation of large bullae on the affected arm (Figure 3). Circa 51 hours
after contact with the plant, he attended the accident and emergency (A&E)
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department at the local hospital. Initially the pain and blistering were restricted to the
arm which had been wrapped around the fig branches—but subsequently he developed
pain and swelling on the left arm, chest, and legs which had also been in contact with
the fig tree. The discomfort progressed such that he was unable to work for
approximately 10 days.
He responded slowly to topical corticosteroids and oral non-steroidal anti-
inflammatories. The symptoms gradually resolved over 4 to 6 weeks (Figure 3).
The history and clinical appearances was pathognomonic of a phytophotodermatitis
which, in these two cases, was secondary to contact with the fig tree.
Phytophotodermatitis is the interaction of plant compounds, most often psoralens,
with sunlight on human skin; this results in an acute dermatitis.
It is usually a
phototoxic reaction, as opposed to a photoallergic reaction. As a result, no prior
sensitisation is necessary and anybody can be affected.
Other types of
phytodermatitis include urticarial dermatitis, irritant contact dermatitis, and allergic
contact dermatitis.
The eruption of phytophotodermatitis usually begins 24 hours after exposure and
peaks at 48–72 hours. Phytophototoxicity may be amplified by both humidity and
perspiration. It typically manifests as a burning erythema that may subsequently
blister, and post-inflammatory hyperpigmentation lasting weeks to months may ensue.
In some patients, the preceding inflammatory reaction may be mild and go
unrecognised by the patient.
Phytophotodermatitis occurs most commonly in the spring and summer when
furocoumarins are at their highest concentration in plants, and when UV levels are
also at their peak. The incidence of phytophotodermatitis is unknown, but will vary
according to the risk of exposure to psoralens. Because furocoumarins are found in a
wide range of wild and domestic plants (Table 1), a variety of patient groups may
become exposed.
Table 1. Examples of plants known to cause phytophotodermatitis, and the main sensitising
compounds associated with them
Family Species Common Names Main Compounds
Apiaceae Ammi majus
Apium graveolens
Heracleum sphondylium
Heracleum mantegazzianum
Pastinaca sativa
Bishop's weed, large bullwort
Cow parsnip, common hogweed
Giant hogweed
5-MOP, 8-MOP, imperatorin
Psoralens, 5-MOP, 8-MOP
5-MOP, 8-MOP, imperatorin, phellopterin
5-MOP, 8-MOP, imperatorin,
5-MOP, 8-MOP, imperatorin, isopimpinellin
Fabaceae Psoralea corylifolia Babchi, scurf pea Psoralens
Moracea Ficus carica Fig Psoralens, 5-MOP
Rutaceae Citrus bergamia
Citrus maxima
Dictamnus albus
Pomelo, pummelo, shaddock
Gas plant
5-MOP, 8-MOP
5-MOP = 5-methoxypsoralen, 8-MOP = 8-methoxypsoralen.
The two cases presented were at very high risk of developing phytophotodermatitis
because of their prolonged and significant contact, high summer levels of
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furocoumarins in the plant, peak summer UV levels, exposed skin, warm temperature,
and perspiration.
Whilst photoallergic reactions are a cell-mediated immune response in which the
antigen is the light-activated photosensitising agent, phototoxic reactions result from
direct damage to tissue caused by light activation of the photosensitiser.
The main photosensitisers in plants are furocoumarins and consist of psoralens (5-
methoxypsoralens, 8-methoxypsoralens), angelicin, bergaptol, and xanthotal (Table
The photochemical excitation of these furocoumarins is induced by UV radiation,
usually within the UVA wavelengths of 320–400 nm (peak activity is around 335
Two types of toxic reactions occur: one oxygen-independent, where the UV-activated
furocoumarins bind to RNA and nuclear DNA; and the other: an oxygen-dependent
reaction where the induced compounds cause cell membrane damage and oedema.
These reactions consequently lead to cell death (sunburnt cells and apoptotic
Ficus carica, which is believed to have originated in western Asia, was brought to the
Mediterranean as early as 5000 BC. In New Zealand, it is commonly cultivated as a
fruit tree in home gardens and appears to be widespread in the North Island
(particularly in northern regions); it can also be found in some areas of the South
Island, particularly in those areas that experience long, hot summers (Melanie
Newfield, personal communication, 2007).
Ficus carica belongs to the Mulberry family (Moraceae). The leaves and unripened
fruit of figs contain the furocoumarins, psoralen, and bergapten, as well as the
coumarins, umbelliferone, 4',5'-dihydropsoralen, and marmesin. The furocoumarins
are lipid-soluble and can penetrate the epidermis with ease.
There are a number of other Ficus species which may cross react with F. carica
including Weeping fig (F. benjamina), Cluster fig (F. racemosa), and Sycamore Fig
(F. sycomorus).
Eating figs does not cause photosensitisation, unless the juice is smeared onto the face.
However, anaphylaxis has been reported after eating figs; in some of these cases, this
may represent a cross-reaction with natural rubber latex.
Although phytophotodermatitis from Ficus carica has been previously reported, it is
often poorly recognised. As the cases reported here illustrate, contact with fig and
other plant sources of furocoumarins can cause severe local reactions.
It is important that awareness is raised amongst the general public—especially those
people whose occupations lead to a greater likelihood of exposure: arborists,
orchardists, forestry workers, and gardeners.
Author information: José G B Derraik, Senior Adviser (Human Health), MAF
Biosecurity New Zealand (NZ), Ministry of Agriculture and Forestry, Wellington;
Marius Rademaker, Hon Associate Professor, Department of Dermatology, Waikato
Hospital, Hamilton
NZMJ 10 August 2007, Vol 120 No 1259 Page 5 of 5
Acknowledgements: We are grateful to Gerald Collett, Alex White, and Ian Barnett
(Treecare Services Ltd, Auckland) for providing us with the precise details of the case
as well as the very useful photographs, which made this case report possible. We also
thank Petr Kocna for allowing us to include his photographs in this article, and
Melanie Newfield (MAF Biosecurity NZ) for relevant information. Climate data were
kindly supplied by National Institute of Water and Atmospheric Research (NIWA).
Correspondence: Dr José G B Derraik, MAF
Biosecurity NZ, Ministry of Agriculture
and Forestry, PO Box 2526, Wellington. Fax: (04) 894 0733; email:
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This case report was corrected on 7 September 2007 to reflect the Erratum at
... Due to the presence of latex, it is suggested that the laborers picking the fruit wear gloves. Latex may lead to skin irritation and corrosion, and consumers eating unripe figs with latex may be subject to oral cavity mucous membrane injury and allergic reactions [33,34]. Latex contains ficins which belong to the papain subfamily in the family of cysteine proteases [30,33]. ...
... Latex may lead to skin irritation and corrosion, and consumers eating unripe figs with latex may be subject to oral cavity mucous membrane injury and allergic reactions [33,34]. Latex contains ficins which belong to the papain subfamily in the family of cysteine proteases [30,33]. The cysteine protease in latex participates in plant defense, and both papain and ficin are toxic to lepidopteran insects, causing growth stagnation or death of the larvae. ...
Full-text available
Background Fig fruit are highly perishable at the tree-ripe (TR) stage. Commercial-ripe (CR) fruit, which are harvested before the TR stage for their postharvest transportability and shelf-life advantage, are inferior to TR fruit in size, color and sugar content. The succulent urn-shaped receptacle, serving as the protective structure and edible part of the fruit, determines fruit quality. Quantitative iTRAQ and RNA-Seq were performed to reveal the differential proteomic and transcriptomic traits of the receptacle at the two harvest stages. Results We identified 1226 proteins, of which 84 differentially abundant proteins (DAPs) were recruited by criteria of abundance fold-change (FC) ≥1.3 and p < 0.05 in the TR/CR receptacle proteomic analysis. In addition, 2087 differentially expressed genes (DEGs) were screened by ≥2-fold expression change: 1274 were upregulated and 813 were downregulated in the TR vs. CR transcriptomic analysis. Ficin was the most abundant soluble protein in the fig receptacle. Sucrose synthase, sucrose-phosphate synthase and hexokinase were all actively upregulated at both the protein and transcriptional levels. Endoglucanase, expansin, beta-galactosidase, pectin esterase and aquaporins were upregulated from the CR to TR stage at the protein level. In hormonal synthesis and signaling pathways, high protein and transcriptional levels of aminocyclopropane-1-carboxylate oxidase were identified, together with a few diversely expressed ethylene-response factors, indicating the potential leading role of ethylene in the ripening process of fig receptacle, which has been recently reported as a non-climacteric tissue. Conclusions We present the first delineation of intra- and inter-omic changes in the expression of specific proteins and genes of TR vs. CR fig receptacle, providing valuable candidates for further study of fruit-quality formation control and fig cultivar innovation to accommodate market demand.
... The aforementioned reaction happens upon contact with F. latex followed by exposure to sunlight, and it is related to the latex content of the photoactive compounds furocoumarins, mainly psoralen and bergapten [25] . It happens mostly in spring when the furocoumarin concentration is at its peak [121] . Besides, F. latex enzymes, such as proteases and amylases, can potentiate the furocoumarin effect due to their keratolytic activity [122] . ...
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Ficus carica tree produces a white sap that is traditionally used for the treatment of skin conditions, such as warts. Ficus carica latex is considered a rich source of proteins and metabolites that have various pharmacological activities. Most of the latex pharmacological activities are attributed to its phenolic content, such as anticancer, antiviral, antioxidant, anti-angiogenic, hepatoprotective, and wound-healing activities. Moreover, Ficus carica latex contains proteases that are involved in the treatments of skin conditions, such as warts, and display antiparasitic activity. Additionally, chitinase enzymes and coumarins are isolated from Ficus carica latex and involved in the antimicrobial activities of latex.
... These particular plants synthesize naturally occurring compounds known as furocoumarins (psoralen isomers) that precipitate phototoxic reactions [2]. After the affected skin comes in contact with furocoumarins and is subsequently exposed to UVA radiation, the psoralens damage cell DNA and membranes leading to cell death and epidermal injury [3]. Patients typically present with skin blisters/vesicles or plaques that are burning or painful and that can evolve into irregularly shaped well-demarcated patches of hyperpigmentation. ...
Full-text available
Phytophotodermatitis, also commonly known as phototoxic dermatitis, is a common skin condition that occurs after contact with certain plants and subsequent exposure to sunlight. It is often confused with skin burns due to the blistering nature of its lesions. We herein report a case of phytophotodermatitis that developed in a 26-year-old male following contact with lime and subsequent exposure to sunlight.
... Psoralen, in particular, is one of the furocoumarins that interact with DNA under UV radiation and cause reactions to occur. One of the plants containing such allergens is Ficus carica [31]. The other such plants mentioned in the literature are Petroselinum sativum, Heracleum laciniatum, Heracleum mantegazzianum, Heracleum giganteum, Quisqualis indica, Brosimum wood, Parthenium hysterophorus, garlic, and Frullania [32]. ...
Full-text available
Purpose of Review Photoallergic contact dermatitis (PACD) is a delayed-type hypersensitivity reaction to a photoactivated allergen applied to the skin. The purpose of this review is to provide comprehensive information about the mechanism of photoallergic contact dermatitis and to make an outline of its etiopathogenesis, clinical features, and treatment methods. Recent Findings PACD lesions are generally localized in areas which are exposed to light. However, reactions may spread to covered areas of the body. Most prevalent photoallergens are present in sunscreens and NSAIDs. The diagnosis of PACD is based on patient history and a clinical examination and is confirmed by a photopatch test which allows the distinct separation between PACD and allergic contact dermatitis. Although the basic treatment for PACD is in form of avoiding photoallergens, topical corticosteroids, antihistamines, and immunomodulatory drugs can also be used in the treatment. Summary Photoallergic contact dermatitis is a skin condition caused by UV light exposure after contact with photoallergen or uptake of photosensitizer agent. PACD should always be kept in mind in a patient with history of photosensitivity.
... Die photochemische und phototoxische Reaktion [7,17] ...
Eine 28-Jährige kommt bei der Rodung eines verwilderten Grundstückes trotz Schutzkleidung mit Riesenbärenklau in Kontakt. Drei Tage später treten flächige, schmerzhafte, teilweise bizarr konfigurierte, streifen- und strichförmige ödematöse Erytheme und Blasen auf (Abb. 1).
Phytophotodermatitis is a nonimmunologic, phototoxic reaction caused by the combination of a topical or oral photosensitizing agents in plants followed by exposure to the long‐wavelength ultraviolet radiation (UVA). Here we describe a lime‐induced phytophotodermatitis that occurred in two family members.
The US Department of Health and Human Services statistics indicate that cases of child maltreatment are rising. This can be an extra burden on an already strained health care system. Although a call to child protective service may be warranted, a thorough history and initial testing may be sufficient to diagnose a child abuse mimic and rule out physical abuse. This testing can help facilitate the investigation and can also prevent unneeded stress on a family. The most common presentation of physical abuse is a skin finding, typically a bruise. A detailed history and physical examination can help differentiate between physical abuse and mimics of physical abuse. Familiarity with mimics can help one in establishing a differential diagnosis and facilitate the testing for physical abuse. As skin findings may be the first indicator of abuse, this article focuses on abnormal skin findings that can mimic abuse and how to differentiate them from abuse. [Pediatr Ann. 2020;49(8):e341-e346.].
Infectious diseases transmitted by animals to humans represent 25% of all reported and compensated cases of occupational diseases among forestry workers in Germany according to the records of the German Workman’s Compensation Insurance of Agriculture. Work-related injuries are the most frequent occupational hazards among forestry workers, followed by arthropod bites and arthropod-borne infections. Forestry workers are at risk of tick-borne diseases such as Lyme borreliosis, tick-borne encephalitis, anaplasmosis, relapsing fever, tularemia, babesiosis, and rickettsiosis. The risk of transmission of Lyme borreliosis after a tick bite is 4%. High seroprevalences of antibodies to Borrelia burgdorferi in risk groups were found in Europe, up to 61.5% in Northern Poland. Lepidopterism develops after contact with caterpillars, for example, Thaumetopoea processionea L. in oak forests and Thaumetopoea pityocampa in pine forests, and moths, for example, Douglas-fir tussock moth Orgyia pseudotsugata, due to the toxic protein in the caterpillars’ setae. Forestry workers may develop hand–arm vibration syndrome symptoms of which are disturbances in the circulation of the fingers (vibration white finger) and peripheral nerves of the hands and arms, dependent upon the frequency with which the chain saw is used. Both exposure to cold in winter and the duration and intensity of woodwork enhance the risk of hand–arm vibration syndrome. Occupational dermatitis attributed to plant irritants is the most common cause of sick leave among forestry workers in California. Sap or latex from tropical trees, particularly Anacardiaceae, such as rengas tree (Gluta renghas), can cause an acute vesicular irritant dermatitis and conjunctivitis in woodcutters clearing rain forests. Phototoxic plants growing at the edge of forests – for example, giant hogweed (Heracleum mantegazzianum) containing furocoumarins – may cause phytophotodermatitis among forestry workers. Aromatic lichen acids may also provoke photosensitivity. Poison ivy (Rhus toxicodendron) – containing urushiol – lichens such as oak moss or tree moss, liverworts in undergrowth, ragweed (Ambrosia), and wood dust from tropical trees, containing, for example, dalbergiones, are the major contact allergens in the forest environment. Patch testing of plants and plant extracts must be considered carefully in order to avoid active sensitization.
Die Kombination von Hautkontakt mit Furocumarin-haltigen Pflanzen und gleichzeitiger Sonnenexposition mit UV-A-Strahlung kann eine Phytophotodermatitis auslösen. Die Hautreaktion erreicht jedoch erst 48 bis 72 Stunden nach Exposition ihr Maximum. Der Zusammenhang zwischen dem auslösenden Ereignis und den Hautveränderungen wird daher oft nicht erkannt.
Phytophotodermatitis is an acute skin reaction that may be easily confused with other causes of contact dermatitis. It is characterized by sunburn, blisters, and/or hyperpigmentation. The reaction takes place when certain plant substances known as psoralens, after being activated by ultraviolet light from the sun, come in contact with the skin. The condition is usually mild and self-limited but hyperpigmentation may persist for many weeks. Failure to recognize phytophotodermatitis in a child may lead to a mistaken diagnosis of child abuse. It is also important to be aware of perfumes and grocery products as causes of this phenomenon.
Plants are nature's most efficient factories for producing a variety of chemicals. Of the more than half million known plant species, only about 12,000 have been investigated, with isolation and identification of about 11,000 naturally occurring compounds. 1,2 Most plant species are considered harmless, and only about 500 are reported to be harmful because of their topical or systemic toxicity.Adverse reactions of skin to plants, referred to as phytodermatitis, resulting from mechanical injury, toxicologie effects (eg, alkaloids), pharmacologic effects (eg, stinging nettle causing liberation of histamine and acetylcholine), contact dermatitis by irritant chemicals, and delayed hypersensitivity reactions involving immunologie mechanisms are discussed in other chapters. Phytophotodermatitis, evoked by several furocoumarins (psoralens) produced by such plant families as Umbelliferae, Leguminosae, Rutaceae, occurs only after contact with a plant (sap, leaves, etc.) and subsequent exposure of the skin to long-wave ultraviolet radiation. There is a considerable overlap because phytodermatitis may result from mechanical injury, chemical irritation, or sensitizing substances.The subject and literature concerning dermatitis and allergic plant dermatitis is voluminous, and our knowledge of the chemical nature of allergens present in plants still is limited. Existing data gathered from the published reports do not necessarily establish that the plants mentioned in the literature are indeed capable of inducing phytophotodermatitis; some plants may concomitantly produce reactions of the skin by direct mechanical trauma, contact irritation, allergic sensitization, photosensitization, or any combination of these factors.1–11This chapter is concerned primarily with plants that contain certain photosensitizing agents that may induce photodermatitis only when skin is exposed to sunlight either inadvertently or deliberately. The reactions are mostly phototoxic in nature1,2: they are invariably not dependent on an antigen-antibody relationship or a cell-mediated hypersensitivity reaction. Following the review of phytophotodermatitis in humans, this chapter also includes a brief survey of phytophotodermatosis in animals.
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 photos ensitiszation and the absence of photoactive furocoumarins in the fruit and its sap remains unexplained.
In several patients the effect of a phototoxic reaction to the juice of fresh figs (ficus carica) was observed as a striped pigmentation on the arms (after rubbing in the fruit juice followed by exposure to the sun), or as a patchy pigmentation of the face after eating fresh figs. Reference is made to the pathogenetic identity of this furocoumarin phototoxic reaction and the clinical transition of ficus dermatitis both to "Berloque dermatitis" (from the oil of types of citrus) and to bullous meadow dermatitis (from the juice of types of heracleum). Reference is also made to the similarity of the therapeutic furocoumarin reaction in PUVA therapy.
The coumarinic compounds of fig leaves (Ficus carica) here examined closely. The furocoumarins psoralen, bergapten and the coumarins umbelliferone, 4',5'-dihydropsoralen and marmesin are present. These substances were determined in a "coumarinic extract" by high pressure liquid chromatography (HPLC). The seasonal variations of the above mentioned compounds were also studied in a series of samples of leaves picked from the same plant, at regular fortnightly intervals during the period 1/VI-2/XI/1979. From the data obtained it is noticeable that the total coumarinic content is maximun--0.5% as compared with the dry weight--in the extract of leaves picked on the first August, while it is lowest in the extract of leaves picked on the 15th June. The quantity of psoralen is always greater than that of bergapten, umbelliferone, 4',5'-dihydropsoralen and of marmesin. The ratio psoralen: bergapten is not constant, but fluctuates extensively with the seasonal variations from 2.8 to 7.7.
We report an anaphylactic reaction which occurred very shortly after ingestion of a fresh fig. The IgE-dependent mechanism was demonstrated on the basis of positivity of the prick test performed with fresh fig (Ficus carica) extract. In addition, we were able to detect specific IgE to the same extract in the serum. The patient did not demonstrate sensitization to other common allergens involved in respiratory and food allergies. However, detection of specific IgE to F. benjamina indicated a sensitization to weeping fig. The CAP F. benjamina was partially inhibited by preincubation of the serum with fig extract, suggesting that these two species of Ficus share some common allergens. In this context, the assumption can be made that weeping fig was responsible for the initial sensitization in this patient.
The importance of hypersensitivity to Ficus allergens is reported. Cross-sensitization between fig (Ficus carica), weeping fig (F. benjamina [Fb]), and natural rubber latex (NRL) was confirmed by RAST inhibition. We performed skin prick tests with fresh Fb tree sap and NRL extracts in 346 consecutive patients and in 151 patients with immediate-type hypersensitivity to NRL. Total serum IgE and IgE antibodies to NRL and Ficus spp. were analyzed in sera. By the RAST-inhibition method, we studied cross-reactivity among latex, fig, and weeping fig. Sensitization to Fb was diagnosed in 23 of the 346 consecutive patients, and the simultaneous presence of latex-specific IgE was highly significant. Of 151 NRL-allergic patients, 35 were also sensitized to Fb. Cross-reacting IgE antibodies recognizing latex and Ficus allergens were demonstrated by RAST inhibition. The present study reinforces the importance of Fb as an indoor allergen. Cross-reacting IgE antibodies to NRL and Ficus spp. allergens are frequently found in the sera of atopic patients. Development of commercially available standardized extracts for skin tests is urgently necessary.