The common fig tree (Ficus carica) is widely cultivated for its sweet, edible fruit, which is generally safe for human consumption. While the ripe fruit is popular, the plant contains compounds that can cause irritating or mildly toxic reactions upon contact. The risk is not from eating the fruit but from exposure to the plant’s internal fluid, particularly when pruning or harvesting.
The Source of Toxicity: Fig Tree Sap (Latex)
The primary source of the fig tree’s irritating properties is the milky-white fluid, known as latex or sap, that oozes from the leaves, stems, and immature fruit when damaged or cut. This latex contains two main types of chemical irritants: furocoumarins and Ficin.
Furocoumarins are phototoxic compounds that sensitize the skin to ultraviolet light. Ficin is a proteolytic enzyme that actively breaks down proteins, contributing to the initial irritation and keratolytic (skin-dissolving) effect of the sap. The sap’s concentration of these irritants is highest in the leaves and stems, making the ripe fruit safe to eat.
Reactions in Humans: Dermatitis and Phototoxicity
Direct contact with fig sap can trigger contact dermatitis, resulting in localized redness, itching, and swelling.
The most severe human reaction is phytophotodermatitis, a two-step process. This condition occurs when skin contaminated with furocoumarins is subsequently exposed to sunlight or UV-A radiation. The furocoumarins absorb the UV light, causing a chemical reaction that damages skin cells and leads to a delayed, exaggerated sunburn.
Symptoms typically begin 24 hours after sun exposure and can progress to painful blisters that mimic second-degree burns, peaking up to 72 hours later. After the acute phase resolves, the affected skin often develops hyperpigmentation, leaving dark spots that can persist for months or years.
Risks to Domestic Animals
Fig trees pose a risk to domestic animals, particularly cats and dogs, through both skin contact and ingestion. The sap’s irritating compounds can cause dermal irritation if a pet brushes against a broken branch.
Ingestion is the more common concern, occurring when pets chew on the leaves, stems, or unripe fruit. When ingested, the sap irritates the mouth and gastrointestinal tract. Common symptoms include excessive drooling, pawing at the mouth, vomiting, and diarrhea. While the reaction is usually mild to moderate, severity depends on the amount consumed and the animal’s size.
Safe Handling and Immediate Action
Preventative measures are the most effective way to avoid adverse reactions when working with fig trees. Wear protective gear, such as long sleeves, trousers, and waterproof gloves, when pruning or harvesting fruit. Avoiding contact with the sap on hot days is also advisable, as sweat and moisture can increase the absorption of furocoumarins.
If skin contact occurs, the affected area should be thoroughly washed immediately with soap and cool water to remove the phototoxic compounds. The exposed skin must then be protected from sunlight for at least 48 hours to prevent the phototoxic reaction from developing.
For severe blistering, signs of infection, or eye exposure, professional medical attention is necessary. If a pet ingests the plant and shows symptoms like persistent vomiting or swelling, contact a veterinarian or a pet poison control center right away.