The Curious Cases of Burn by Fig Tree Leaves.

Phytophotodermatitis is a condition which is caused by contact with some plants containing furocoumarins. Furocoumarins in sap of fig tree are the main cause of its irritability when come in contact with the skin. The main symptoms are burning sensation and pain, itchy erythema, and edema, which usually begin 24 h after exposure. The leaf and root sap of the fig tree are the most potent parts causing irritant reaction. We report four children who were playing with fig tree leaves during a family picnic. They were referred to a burn center with second-degree burn in about 10% of total body surface area, due to phytophotodermatitis. Most people are not aware of the potential adverse effect of the plant. The improvement in general knowledge about the dangers of contacting fig tree leaves and sap and the benefits of suitable coverage at the time of harvesting or contacting fig tree may prevent such adverse effects.

Introduction

One of the essential cautions when touching plants is their potential toxicity and effects on the skin. Phytophotodermatitis is a condition which is caused by contact with some plants containing furocoumarins followed by exposure to sunlight. The most potent light wave for this condition is ultraviolet A (UVA) light with a wavelength between 320 and 380 nm.[1]

Fig tree (Ficus carica L.) is one of the plants that may cause this reaction. The tree grows in warm regions all over the world and is a common and favorite tree in these areas.[2] In complementary medicine, the sap of fig tree is thought to be useful in some diseases, especially in dermatologic diseases such as vitiligo or psoriasis.

The sap of fig tree contains some enzymes which are the main cause of irritability of the sap. Furocoumarins (5-methoxypsoralen) is one group of these enzymes which protect leaves of the tree from fungal pathogens. In contact with skin, it may cause cell death after exposure to UV light by cross-linking of the DNA that blocks cell division, DNA repair, and DNA synthesis. These harmful changes are more common in epidermal DNA and represent as blistering and vesicle formation.[134]

Leaves of fig tree contain psoralen and bergaptol.[5] Psoralen concentration is more than bergaptol, so it is the main agent causing phototoxic reaction by the fig leaf. There are other enzymes with keratolytic effect in fig latex, which increase the effect of furocoumarines such as lipodiastase, amylase, and lipase.[6] The main symptoms of phytophotodermatitis are burning sensation and pain, itchy erythema, and edema, which usually begin 24 h after exposure. Vesicles and bullae may appear approximately 48–72 h after exposure.[1] We expect hyperpigmentation at the site of burning in the chronic phase.

Here, we present four cases of second-degree burn due to exposure to pounded fig leaves.

Case Report

On May 29, 2016, four children (two girls and two boys, aged 8–10 years), from one of the surrounding cities, were admitted to the Burn Center of Imam Reza Hospital in Mashhad, in the northern East of Iran.

They had been admitted to a general hospital with hyperreactive symptoms, 2 days ago [Figures 1 and 2]. They had gone to picnic with their families in a sunny and warm day. While playing near the river, they collected the fig tree leaves [Figure 3] and pounded them to make color for painting their upper and lower extremities. About 8 h later, they all felt a burning sensation in their hands and feet, and they were admitted to the hospital. They received treatment for hypersensitivity and were referred to our burn center with 10%–13% second-degree burn.

Figure 1

Phytophotodermatitis in three children which affected 10%–13% of body surface area. Erythema and bulla formation is prominent

Figure 2

Vesicle formation was more prominent in the right upper arm of the forth patient

Figure 3

A sample of leaves and fruits of plants which caused damage was brought by parents to hospital

In our burn center, appropriate treatment including unroofing of bullae, nonadherent dressing, and analgesic medications was implemented. In a few days, signs and symptoms of hypersensitivity reduced, and all wounds epithelialized. In follow-up visits, only hyperpigmentation in affected areas was noted.

While there was no volunteer, the corresponding author decided to perform a patch test on himself with a paste prepared by pounding the fig tree leaves. He put the paste on a marked area on his left forearm for 1 h [Figure 4a] and then exposed the area to the sunlight for about 2 h. There was no reaction after removing the paste, but a mild burning sensation started almost immediately [Figure 4b]. After 6 h, the test area and its surrounding skin were erythematous. After 24 h, the erythema and edema was more prominent and on day 2, some vesicles appeared [Figure 4c]. On day 5, we removed the vesicle and a second-degree burn appeared in patch test area and around it [Figure 4d]. Surprisingly, the reaction was more extensive than the test area, and almost all of the medial side of forearm was affected by this reaction.

Figure 4

(a) Patch test with fig tree leaves. (b) The test area had a normal appearance after removal the paste. (c) Vesicle formation on day 2. (d) A second-degree burn appeared after removal of vesicles on day 5

Discussion

Many plants including parsnip, cartwheel flower, fennel, parsley, caraway seed, aniseed, coriander, celery, and fig may cause phytophotodermatitis.[7] The fig tree is a popular tree and planted in widespread areas of West Asia. Most of the time there is hot weather and plenty of sunshine, in these areas; this may facilitate phytophotodermatitis reaction. Summer and spring seasons provide a much higher concentration of psoralen and bergapten in the fig tree,[5] which means that it can cause more irritant reaction during this time.

The leaf and root sap of the fig tree are the most potent parts of tree causing the reaction.

Our patients were unfortunate that all of these factors were present at the time of event.

Some authors believe that the synthesis of acute phase proteins including interleukin-1 and tumor necrosis factor-α may have a role in hyperreactive response to UVA. As the synthesis of acute phase proteins is a time consuming process, it may explain the cause of delay in presentation and protracted duration of symptoms and signs.[8]

The appropriate treatment for this condition is simple nonadherent dressing and analgesic drugs. Topical or systemic steroids have been suggested by some investigators. Sun protection to prevent hyperpigmentation due to exposure to UV light is advised.

The differential diagnoses of phytophotodermatitis include impetigo, child abuse, superficial lymphangitis, and larva migrans.[9] Our patients had a straightforward history, and their parents brought a sample of fig tree leaves with their children to the hospital.

Severe burns as much as 81% of body surface area by fig tree leaf tea bathing has been reported.[10] Hence, promoting people awareness about the effects of contact with fig tree leaves without coverage can be beneficial. Fig harvesters, packers, and workers in the food industry are especially prone to this form of sensitivity. Wearing gloves, long-sleeved shirt, full-length pants, a hat, and full-coverage eye goggles (not just glasses) when pruning fig trees may be helpful.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.