What is plantdermatitis?
Plant dermatitis is aninflammationof the skin caused bytopicalcontact with a plant or plantconstituent.
Phytodermatitis is the formal medical name for plant dermatitis, and it may be anirritantcontact dermatitis,allergic contact dermatitis, orphytophotodermatitis.
Contacturticariaand mechanical irritation can also be due to plants.
Common plants that cause dermatitis
Who gets plant dermatitis?
Plant dermatitis can affect anyone in contact with the specific plant component including the sap, bark, wood, leaf, stem, flower, pollen, or fruit. Exposure may be:
- 偶然的接触如刷牙rhus treewhen walking past
- Airbornedue to plant-associatedaeroallergens, for examplecompositaeallergy
- From gardening and cooking activities
- Occupationalincludingflorists,farmers, chefs andfood handlers, fruit pickers, and horticulturists.
- From use of plant-basedessential oilsandfragrancesfound in topical applications, diffusers etc. such astea tree oil.
What causes plant dermatitis?
- Chemical or mechanical irritant
- Skin injury damaging the skin barrier
- Can affect anyone with sufficient exposure
- Chemical irritant such asseaweedtoxins
- Mechanical irritant eg,Bindii dermatitis
- Contactallergen
- Delayed (type 4)hypersensitivityreaction
- Only affects someone with an immune-mediated allergy to it
- Examples includeprimula,poison ivy,grevillea
- Phytophototoxicity
- Plant-derived phototoxin
- Furocoumarins (psoralens) eg, sap ofcow parsnip,limepeel oil
- Skin reaction following contact is induced by UVA in sunlight
- Plant-derived phototoxin
- Contact urticaria
- Non-immunological, for example formic acid in stinging nettles
- Immunologicaleg,latex, the sap from rubber trees
What are the clinical features of plant dermatitis?
- Asymmetrical
- Patterned such aslinearor spattered
- Erythema, blistering,scaling, or cracks
- Distributionrelative to contact site:
- Localised— usual pattern
- lips inallergic contact cheilitisorfingertip dermatitis
- eyelid dermatitisif airborne allergen
- Involvement beyond initial contact site — uncommon
- for example accidental transfer of allergen or irritant from fingertip to eyelid
- Localised— usual pattern
- Onset
- Rapid ifacuteirritant,辐透otoxic, or contact urticaria
- Delayed whilesensitisationdevelops in allergic contact, then rapid on subsequent exposure
- Symptoms
- Burning pain with irritant or phototoxic reactions
- Itchy if allergic contact
- Contact urticaria may cause burning, tingling, or itch
Plant dermatitis
临床特征如何不同在不同类型啊f skin?
- Erythema may be difficult to observe in skin of colour.
- Postinflammatoryhyperpigmentationis more pronounced in dark skin compared to fair skin.
What are the complications of plant dermatitis?
- Secondarybacterialinfection
- Disseminatedsecondaryeczema
- Chronic辐透osensitivitydermatitis [seeChronicactinicdermatitis,Compositae allergy]
- Pollen-food allergysyndrome
- Systemiccontact dermatitis
How is plant dermatitis diagnosed?
Plant dermatitis should be suspected clinically on history and examination. Tests may be undertaken to clarify or confirm the diagnosis.
- Patchtesting
- Open application test
- Skin prick testing
- Photopatch testing
- ImmunoglobulinE testseg, RAST for latex allergy
What is thedifferential diagnosisfor plant dermatitis?
- Reactions to moths, caterpillars, insects, and otherarthropods
- Contact reaction to pesticides used on plants [seePhotocontact dermatitis]
- Other forms ofdermatitis
- Psoriasisand other conditions showing theKoebnerphenomenon
What is the treatment for plant dermatitis?
General measures
- Minimise contact with the relevant plant
- Protective clothing
- Remove the implicated plant from the garden
- Sun protection
- Avoid aggravating the problem with potentially irritating orallergenictopical applications
- Cool compress
Specific measures
- Topicalororalcorticosteroidsfor the acuteinflammatoryphase
- Chronic plant dermatitis may require systemic immunosuppressant medication
What is the outcome for plant dermatitis?
Plant dermatitis is usuallyself-limitingprovided further contact with the implicated plant is avoided, although postinflammatory hyperpigmentation maypersistfor weeks or months. A true plant allergy persists lifelong.
Some forms of contact are unavoidable such as in airborne compositae allergy and a chronic辐透osensitivedermatitis may follow.