Plants and plant products cause many different types of skin reactions, most commonly contact dermatitis. Their negative effects on the skin may be due to toxic, allergic or irritant effects.
These types of reactions are very common in people who garden, and they also account for a significant percentage of occupational dermatoses occurring in gardeners, florists, farmers, botanists and foresters. Skin lesions can appear upon contact with various plant elements - stems, flowers, fruits, pollen, roots or leaves.
Adverse skin reactions of plant origin can take the form of irritant contact dermatitis (mechanical or chemical), allergic contact dermatitis, urticaria (allergic and non-allergic) and phytophototoxic reactions. In addition, due to the presence of thorns or hairs, some plants are susceptible to mechanical damage to the skin and secondary bacterial and fungal infections, such as sporotrichosis.
Allergic reactions caused by plants can be immediate (type I immune response) or delayed (type IV immune response). Wearing protective gloves and thoroughly washing the skin after handling plants can reduce the occurrence of some skin reactions 1-3.
Undesirable skin reactions of plant origin caused by irritation
The content of the article
Irritant contact dermatitis is the most common dermatosis caused by plants. A large proportion of occupational dermatoses occur among gardeners, florists, breeders, farmers, and fruit and vegetable sellers.
Both mechanical factors and chemical compounds contained in plants can cause skin reactions due to irritation. Depending on the causative factor, a distinction is made between mechanical irritant contact dermatitis (MICD) and chemical irritant contact dermatitis (CICD). They can stand alone or overlap each other. Irritating factors:
- thorns;
- thorns;
- spiny hairs (trichomes);
- pointed leaves on the surface of stems or leaves.
The clinical picture of irritant contact dermatitis is varied: from mild chronic eczema of the fingers associated with irritation by plant hairs to acute, toxic, severe reactions caused, for example, by exposure to alkaloids in plant sap. The intensity of symptoms depends on the individual skin barrier, as well as on the amount and duration of action of the irritant.
Mechanical irritation occurs as a result of injury caused by spines or rough hairs located on the surface of leaves or stems or by the sharp edge of leaves. Examples are papular changes with itching occurring in combines and straw harvesters as a result of contact with the sharp hairs of certain grasses or cereals (eg barley, rice, millet, bamboo) or irritating eczema after contact with borage herbs containing spiny hairs. Also, hairs on the stems and leaves of tomatoes can cause irritation, burning, itching and paresthesia.
Typical mechanical injuries are caused by the spines of many types of tropical plants - cacti and succulents. A particular form is a lumpy, itchy rash, often misdiagnosed as scabies caused by contact with glochidia (Opuntia spp. for short). The sharp leaves of holly (family Aquifoliaceae), agave (family Agavaceae), rose thorns (family Rosaceae) or bougainvillea thorns (family Nyctaginaceae) are also typical examples of plant elements that cause mechanical damage to the skin.
Many plant species contain sap containing substances that cause chemical contact dermatitis when irritated. Compounds with high irritant potential include calcium oxalate crystals present, for example, in onion and garlic bulbs (Allium), daffodils (Narcissus), hyacinths (Hyacinthus) and tulips (Tulipa).
Contact with daffodil bulbs (Narcissus spp) causes the most common form of contact dermatitis among gardeners (daffodil itch, lily rash) with mild clinical manifestations of dryness, flaking rashes and cracks.
In turn, tulips from the Liliaceae family, in addition to calcium oxalate, also contain the allergen tulipalin A. Their bulbs have a sharp film that can cause mechanical injuries. Contact with these plants may result in superimposed allergic contact dermatitis with irritant reactions and typical clinical symptoms. For example, manufacturers develop cracks, hyperkeratosis on the fingertips, paronychia and trophic changes in the nails. In some cases, severe eczema occurs with pimples on the fingers or hands.
Also highly irritating are species belonging to the spurge family (Euphorbiaceae) - severe acute contact dermatitis with swelling of the eyelids can occur due to the action of tigliin alcohol polyhydroxide esters in the sap of these plants, and contact with the conjunctiva can cause blindness.
To make a diagnosis, it is necessary to identify the plants with which the patient has been in contact. In mild cases, symptoms often resolve on their own. If there are thorns, hairs or other plant fragments on the skin, they must be removed.
White spots with dark edges on tomatoes - septoria
If cloudy white spots with dark edges start from the lower leaves and then spread further, if they leave the impression of a gray coating, then most likely this is septoria - a very dangerous fungal disease. If you do not take any action, black dots will appear in the middle of the white spots, the leaves will darken and fall off. The disease can affect other leaves, stems, and fruits. The plant could become infected if the soil was poorly prepared; fungal spores could remain in it. The seed material could be contaminated, which is why the seeds need to be treated before sowing. Septoria usually develops in July because it is triggered by high humidity and intense heat.
Spots on tomato leaves and what to do? See here
Infected plants must be removed and destroyed. The disease is difficult to treat. At the initial stages of the disease, plants are treated with fungicides: Bordeaux mixture, Oksikhom, Hom, Revus. Effective biological products: Fitosporin M, Alirin.
Allergic contact dermatitis
In addition to skin irritation reactions, some plant species can also cause allergic contact dermatitis. The most important plant allergens include, but are not limited to, urushiol (present in plants of the Anacardiaceae family, including Toxicodendron spp.), quinones, and abietic acid (found in pine or rosin resins).
Toxicodendrons and poison ivy have a high allergenic potential, which cause serious skin reactions with a tendency to generalize. In tropical climates, cashews and mango trees are a member of the cashew family, causing frequent allergic reactions among growers, harvesters and processors.
Representatives of chrysanthemums can also cause allergic contact dermatitis, and species of the chamomile family (Compositae) can cause airborne reactions with the appearance of rashes on the skin of the face.
The most common clinical symptoms:
- erythema;
- swelling with blisters;
- blisters;
- itching
Severe systemic allergic reactions may occasionally occur.
If symptoms appear after contact with the plant, it is necessary to wash the affected area or rinse the entire body with running water. In the early stages of the reaction, topical corticosteroids help relieve symptoms. For severe allergic reactions, the use of general glucocorticosteroids is sometimes necessary.
Injuries
Seedlings receive life-threatening injuries due to the fault of domestic animals. But this only happens in those families where the owner is not involved in raising the animal. In case of an offense - an overturned box of seedlings - you should shout menacingly, wag your finger, catch the pet, wrap it in a blanket and lightly flick your index finger at the very tips of the ears - the tender places where the nerve endings are located. This will not lead to damage to health, but the pet will feel discomfort and will no longer misbehave.
Article on the topic
Plant ingredients and water. Making soil for seedlings
Hives
Plants can cause urticaria by an immune and, more often, non-immune (toxic) mechanism.
Immune urticaria, resulting from IgE-mediated mast cell degranulation, usually occurs in people with chronic, persistent exposure to fresh fruits or vegetables, often with a history of atopy.
In principle, any plant can be a trigger for immune urticaria - the most commonly cited in the literature are: celery (Apium graveolens), potato (Solanum tuberosum), mustard, kale (Brassica oleracea), pepper, lettuce, strawberries and Brazilian rubber (Hevea brasiliensis) , which is the most important raw material for latex production.
In latex products, the allergens are surface proteins that are not sufficiently extracted from the Brazilian rubber tree, which can cause severe hives. People with latex allergies may experience a cross-reaction to fruits such as bananas or apples. Other fruits (kiwi, pineapple, peach, plum, mango, melon, lemon), vegetables (tomatoes, onions, garlic, carrots), herbs, grains and trees are also potential triggers.
Plants after heat treatment or deep freezing are characterized by less allergenic potential.
Clinical symptoms usually appear approximately 30 minutes after contact with the plant in the form of skin itching, erythema, urticaria, burning, and sometimes blisters and exudate also appear.
Immune contact urticaria is one of the occupational dermatoses among producers and sellers of fruits, vegetables and spices (beans, lettuce, mustard, pepper), cotton growers, carpenters working with southern wood.
A more common plant-based form of urticaria is non-immune urticaria. The reaction usually occurs after contact with nettle (Urtica dioica), the most common cause of herbal urticaria. The surface of the leaves of this group of plants have sharp stinging and stinging hairs containing histamine, serotonin and acetylcholine.
Skin lesions appear in all exposed people, and hives blisters reach their maximum size approximately 3 to 5 minutes after exposure. Subjective symptoms, such as burning and itching, disappear within 1-2 hours, and tingling can persist for up to 12 hours. Non-immune urticaria can also be caused by many other plant species.
Treatment of urticaria
Small spots with a dark brown color - Fomoz
Numerous small dark brown to black spots appear on the leaves, which may form concentric rings as they increase in size. This is Phomaz (Phomosis rot) . In case of illness
Fruits, both unripe and ripe, are affected. Phoma can be identified by the characteristic brown spot that appears near the stalk. Then it increases in diameter, but not much. Typically the spot reaches a size of about 3 centimeters. The main spread of rot occurs inside the fruit.
The pathogenic fungus can survive in the soil, in contaminated plant debris, as well as on pepper plants and closely related weeds. The spread of the disease is facilitated by high humidity and fertilizing rich in nitrogen. Spots on tomato leaves and what to do? See here
As a preventive measure, the soil is disinfected, and it would not be a bad idea to treat the internal parts of the greenhouse with a disinfectant solution.
Treatment is carried out with the following drugs: Bordeaux mixture, Hom, Oxychom. Diseased fruits must be collected and destroyed.
Phytophotodermatosis
Such reactions are also known as plant-induced phytophotodermatitis. This is a group of skin reactions that occur by a non-immune mechanism after skin contact with plants containing phototoxic substances and exposure to ultraviolet radiation.
The most common compounds present in plants that cause phytophotodermatitis are furanocoumarins (psolarens, angelicins). They are present among others in the celery family (Apiaceae), which includes, for example, fennel, parsley, celery, lovage, Sosnowski's hogweed. And also in the Rutaceae family, which includes citrus fruits, rue and bergamot.
These reactions often occur in people who sunbathe in meadows, mow grass, and in children playing in the garden. The typical clinical picture is blisters on an erythematous substrate, well demarcated, affecting exposed skin areas (face, upper and lower extremities), with characteristic hyperpigmentation.
Brown spots on tomato leaves - cladosporiosis
Brown spots on tomato leaves appear first in the lower part of the bush, then spread to the upper leaves. After some time, a dark velvety coating forms on these spots. Less commonly, flowers and fruits are infected, which turn brown and fall off if infected.
These are clear signs of the spread of the dangerous fungal disease cladosporiosis ( brown spot, leaf mold. Spots on tomato leaves and what to do? See here
Treatment methods
Treatment tactics depend on the degree of skin damage and the general condition of the patient.
- In case of minor changes, it is usually sufficient to wash the area of contact with the plant with soap and water, preferably 5-10 minutes after exposure, and the symptoms will disappear spontaneously.
- Cool, moist compresses can be used to reduce the burning, stinging, or pain sensation.
- It is recommended to avoid exposure to sunlight for at least 48 hours. and the use of creams with a UV filter.
In patients with more severe skin lesions due to irritation reactions, allergic contact dermatitis or phytophototoxic reactions, topical glucocorticosteroids are used. For bacterial superinfection - with the addition of local antibiotics. Oral antihistamines are also helpful.
In case of very severe reactions, oral or parenteral administration of glucocorticosteroids is indicated.
Typical failures when growing tomatoes
Fertilization does not occur - the reason is high humidity or high temperature in the greenhouse (spray with “Bud” or “Ovary” preparations in the morning and do good ventilation of the greenhouses).
The ovaries fall off - the reason is excessive feeding of tomatoes with nitrogen or manure; For the same reason, there is a delay in fruiting and excessive growth of the aboveground part.
Slow growth of ovaries is caused by prolonged cold weather, cloudy weather or a sharp change in day and night temperatures (in this stressful situation, you should feed with calcium nitrate - 3 tablespoons per 10 liters of water, half a liter of solution per bush).
conclusions
Skin reactions caused by plants can be divided into:
- irritant contact dermatitis (mechanical or chemical);
- allergic contact dermatitis;
- urticaria (immune and non-immune);
- phytophotodermatitis.
The clinical picture is varied - from mild skin symptoms in the form of erythema, itching to severe toxic or allergic reactions. To make a correct diagnosis, a thorough interview of the patient should be conducted to determine exposure to individual plant species.
Preventive measures play an important role: using gloves when working with plants and thoroughly rinsing the skin with water after contact.
Treatment includes topical corticosteroids, oral antihistamines, and for severe reactions, general corticosteroids.
Sources
McGovern T. Dermatoses caused by plants. Dermatology. Fourth edition, 2022.
- Modi GM, Doherty SB, Katta R, et al. Plant irritant contact dermatitis. Dermatitis, 2000.
- Sasseville D. Dermatitis from new world plants. Euro J Dermatol 2009.
- Esser PR, Mueller S, Martin SF. Contact dermatitis caused by plant allergens. Planta Med 2022.
- Lovell RF. Occupational dermatitis caused by plants. Professional dermatology. Manson Publishing 1998.
- Bhatia R., Alikhan A., Maybach H.I. Contact urticaria: current scenario. J Dermatol 2009.
- Lehmann P. Photodermatosis. In: Burgdorf WHC, Pelzig G, Wolff HH, et al. Dermatology. Chelej Publishing, 2022.
