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Skin manifestations caused by Brazilian traumatic, allergenic, and venomous plants: main species, therapeutic and preventive measures

V. Haddad Junior About the author

Abstract

Brazilian flora is very rich and a large number of specimens can cause adverse reactions, from mild erythema to cutaneous necrosis. Plants or vegetal extracts are always suspected of contact dermatitis; they are found in all types of environments, including dwellings. Other harmful effects, which can be identified by clinical manifestations and the aid of the patient, are phytophotodermatitis, traumas, thorn infections, chemical irritations, or urticaria caused by Urtica sp. Knowledge on the most important plants and their effects on human skin are very useful, and diagnosis is very important in treatment of the complications.

Brazilian plants; envenoming by plants; Anacardiacea; Phytophotodermatitis


REVIEW ARTICLE

Skin manifestations caused by Brazilian traumatic, allergenic, and venomous plants: main species, therapeutic and preventive measures

Haddad Junior V.

Departmento de Dermatologia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista-UNESP, Botucatu, São Paulo, Brasil

Correspondence

ABSTRACT

Brazilian flora is very rich and a large number of specimens can cause adverse reactions, from mild erythema to cutaneous necrosis. Plants or vegetal extracts are always suspected of contact dermatitis; they are found in all types of environments, including dwellings. Other harmful effects, which can be identified by clinical manifestations and the aid of the patient, are phytophotodermatitis, traumas, thorn infections, chemical irritations, or urticaria caused by Urtica sp. Knowledge on the most important plants and their effects on human skin are very useful, and diagnosis is very important in treatment of the complications.

Key words: Brazilian plants, envenoming by plants, Anacardiacea, Phytophotodermatitis.

INTRODUCTION

Brazilian flora is one of most diverse on the planet. Traumatic, allergenic and venomous plants are found everywhere in the country, including in houses. Therefore, the risk of human contact increases, with traumatic, allergic or toxins provoked manifestations, which is seen more frequently than in the past. Practically all these plants can be associated with dermatitis, which hinders diagnosis of the responsible species (2,8,9,14,15). Another common problem is the introduction of exotic species, especially ornamental plants, although plants can also be introduced or adapted to Brazilian forest environments for alimentation or research. Some plants have toxin or venom in their flowers, leaves, stems, and roots, but the most common harmful mechanisms are physical, traumatic, and allergic actions (2,9,15).

Although accident incidence is high for contact frequency, epidemic data is scarce (2,8,9,14,15).

A practical classification of the effects to human skin can be obtained using the harmful effects of the plants as a starting point.

Contact urticaria

Urtigas or nettles (Urtica sp) present hollow bristles with sharp tips on the surface of the leaves; these can penetrate human skin and liberate inflammation mediators (mainly histamine and acetylcholine) (4,15). Urtica dioica is very common in Brazil and found close to garbage deposits and stables (14) (Figure 1). The manifestations are urticarial, with intensely itchy erythematous and edematous plaques (Figure 2). The reaction happens some minutes after contact; it is less commonly caused by tulip bulbs, perfumes, spices, nuts, coffee, and other vegetables (8,9). Treatment is usually with antihistamines and topical corticosteroids.



Phytophotodermatitis

Psoralens are responsible for reactions, linking to cellular DNA and increasing sensitivity to light (2,9). The classic lesions are initial vesicles and blisters over an erythematous skin with evolution to subsequent melanosis, with linear or bizarre distribution, which appears after solar exposure in leisure environments (11). Phytophotodermatites or phytophotomelanosis are mainly associated with citric fruits (2,9,12), figs (16), celery, parsley, green onions, and mango trees (Figure 3). It has been used for thousands of years with mama-cadela (Brosimum gaudichaudii), a plant of the Brazilian cerrado, in the treatment of vitiligo (Figure 4).



Topical corticosteroids relieve the symptoms of hiperpigmentation, but do not interfere in its evolution.

Dermatitis from physical and chemical irritants

There are no allergic phenomena. Clinical manifestations vary from mild erythema to extensive cutaneous necrosis (8,9).

Physical causes include thorns, bristles, and structures that can penetrate human skin. Such as rosebushes, cacti (7,10), bamboo, and palm trees. These can be important complications, the introduction of plant material can cause foreign body granulomas, and also introduce bacterial agents of common infections, as staphylococcus and streptococcus, and severe infections, as tetanus, sporotrichosis, and mycobacteriosis (2,8,9). Whenever possible, harmful structures should be extracted from the victim's skin.

Chemical aggression occurs when there is skin contact with toxic saps (containing alkaloids, proteolytic enzymes, saponins, anthraquinones, phenolic compounds, or calcium oxalate crystals) (2,9). For example, the Euphorbiacea family ("colchão-de-noiva" and "bico-de-papagaio") and Anthurium species have a milky sap that can irritates the skin and mucous membranes due to calcium oxalate crystals (5). The Euphorbia milli (crown-of-thorns, "colchão-de-noiva") is a plant native to Madagascar that has calcium oxalate in its sap and thorns on the branches (8) (Figure 5).


Some plants present irritating mechanisms that act on the skin and mucous membranes. The same plants are used for ornamental or culinary purposes, and, consequently are in frequent contact with human beings. A classic example is the peppers (genus Capsicum), which have a potent irritating agent in the capsaicin that provides their pungency and can be used as a pain process blocker, by acting on the P substance (pain mediator). Other examples are "comigo-ninguém-pode" (Dieffenbachia sp), pineapple, and tobacco. The lachrymatory effect of onions is caused by propenylsulphenic acid (2,9).

Any plant contact can cause mucous or cutaneous rashes, which may present systemic manifestations. Immediate or early intensive washing of the site can help. Corticosteroid creams are useful in the control of the symptoms (8,9,14).

Allergic Contact Dermatitis

Allergic phenomena of sensitization (type IV) can be caused by contact with any plant or vegetable extract, but plants from the Anacardiacea family are the most important in the genesis of this process (1,2,8,9,14,15).

These plants possess channels with a resinous sap that mixes with air, disseminating into the environments near the trees (9). They belong to the Poison ivy and Poison oak (genus Rhus or Toxicodendrum) family; that are responsible for most of the dermatitis caused by plants in the USA. The cashews (Anacardium occidentale) (3,6), mangoes (Mangifera indica), cajás (Spondias mombin), umbus (Spondias tuberosa), and aroeiras are native to Brazil, and are feared by Brazilian rural workers.

The most common species of aroeiras are Lithraea molleoides, the white aroeira or aroeira-brava, Lithraea brasiliensis, the aroeira-do-mato, Schinus terebenthifolius, the red aroeira, and Schinus molle, the aroeira-salso (8,14) (Figure 6). They are found all over Brazil, especially the Southeast region. In popular medicine, the peel and/or leaves are cooked and used to accelerate cicatrization (in ulcers, arthritis, erysipelas, etc) and also as infusion for diarrhea, bronchitis, and other inflammations (13).


The injuries caused by aroeiras, which liberate irritating substances from their leaves, are serious and common in the country. Manifestations settle down in one or two days, with acute eczema in exposed areas (primary, induced by light, (13) and secondary, in the genitals). It is classic to hear that "the victim was asleep under the aroeira". The resolution can take up to three weeks (Figures 7 and 8).



Treatment uses topical or systemic corticosteroids, depending on the extension of the dermatitis. Up to 80 mg doses of systemic steroids can be necessary to control signs and symptoms.

ACKNOWLEDGEMENTS

The author is thankful to Eliete Correa Soares Nóbrega de Jesus and Maria Regina Cavariani Silvares for the images of Urtica sp present in this work.

  • Correspondence to
    V. Haddad Júnior - Departmento de Dermatologia e Radioterapia,
    Faculdade de Medicina de Botucatu, Universidade Estadual Paulista
    Distrito de Rubião Júnior, s/n, Caixa Postal 557
    18618-000, Botucatu, São Paulo, Brasil
    Email:
  • Received: July 27, 2003

    Accepted: July 27, 2003

    Published online: September 10, 2004

    • 1 ADAMS RM. Dermatitis caused by poison ivy and its relatives. Curr. Concepts Skin Disord., 1988, 9, 5-9.
    • 2 AVALOS J., MAIBACH HI. Dermatology botany Boca Raton: CRC Press, 1999 440p.
    • 3 DIOGENES MJ., DE MORAIS SM., CARVALHO FF. Contact dermatitis among cashew nut workers. Contact Dermatitis, 1996, 35, 114-5.
    • 4 EMMELIN N., FELDBERG W. The mechanism of sting of the common nettle (Urtica dioica). J. Physiol., 1947, 106, 440-5.
    • 5 FRANCESCHI VR., HERNER HT. Calcium oxalate crystals in plants. Bot. Rev., 1980, 46, 361-426.
    • 6 GARCIA F., MONEO I., FERNANDEZ B., GARCIA MENAYA JM., BLANCO J., JUSTE S., GONZALO A. Allergy to Anacardiaceae: description of cashew and pistachio nut allergens. J. Investig. Allergol. Clin. Immunol., 2000, 10, 173-7.
    • 7 GELBARD MK. Removing the small cactus spines from the skin. JAMA, 1984, 252, 3368.
    • 8 HADDAD Jr.V. Plantas e dermatologia. In: DIÓGENES MJN., GONÇALVES HS., NEVES RG. Atlas de dermatopatologia tropical, 2.ed. Rio de Janeiro: Medsi Editora Médica e Científica, 2001: 127-32.
    • 9 LOVELL CR. Plants and skin Oxford: Blackwell Scientific Publications, 1993. 272p.
    • 10 MCMANIGAL AS., HENDERSON JC. Mycobacterium marinum infection associated with cactus spine injury. J. Med. Technol., 1986, 3, 256-6.
    • 11 OLIVER F., AMON EU., BREATNACH A., FRANCIS DM., SARATHCHANDRA P., BLACK AK., GREAVES MW. Contact urticaria due to the common stinging nettle (Urtica dioica) - histological, ultra-structural, and pharmacological studies. Clin. Exp. Dermatol., 1991, 16, 1-17.
    • 12 PATHAK MA. Phytophotodermatitis. Clin. Dermatol., 1986, 4, 103-21.
    • 13 SANTOS OLR., FILGUEIRA AL. Dermatites fitogênicas - A propósito de dois casos de fotossensibilização por aroeira. An. Bras. Dermatol., 1994, 69, 291-5.
    • 14 SCHVARTSMAN S. Plantas venenosas e animais peçonhentos São Paulo: Sarvier, 1992. 288p.
    • 15 SCOTT S., THOMAS C. Poisonous plants of paradise: first aid and medical treatment form Hawai' i' s plants Honolulu: University of Hawai' i' s Press, 1997 178p.
    • 16 SERPA SC., SANTOS OLR., OLIVEIRA WN., FILGUEIRA AL. Queimaduras extensas provocadas pela folha de figueira (Ficus carica). An. Bras. Dermatol., 1996, 71, 443-6.

    Correspondence to V. Haddad Júnior - Departmento de Dermatologia e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista Distrito de Rubião Júnior, s/n, Caixa Postal 557 18618-000, Botucatu, São Paulo, Brasil Email: haddadjr@fmb.unesp.br

    Publication Dates

    • Publication in this collection
      24 Sept 2004
    • Date of issue
      2004

    History

    • Accepted
      27 July 2003
    • Received
      27 July 2003
    Centro de Estudos de Venenos e Animais Peçonhentos (CEVAP/UNESP) Av. Universitária, 3780, Fazenda Lageado, Botucatu, SP, CEP 18610-034, Brasil, Tel.: +55 14 3880-7693 - Botucatu - SP - Brazil
    E-mail: editorial.jvatitd@unesp.br