Irritant contact dermatitis (ICD) from plants is a very common phenomenon and accounts for the vast majority of plant dermatoses. Potential irritant plants and plant products can be found almost anywhere people are found: in the home, garden, workplace, and recreational setting. It is therefore essential to have a basic understanding of the various plant-derived physical and chemical irritants in order to formulate a complete differential diagnosis when evaluating a case of apparent contact dermatitis.
The common mechanical plant irritants include thorns, spines, glochids, trichomes, and sharp-edged leaves. Many chemical irritants have yet to be elucidated, but known culprits include calcium oxalate, protoanemonin, isothiocyanates, bromelain, diterpene esters, alkaloids, and other chemical irritants such as naphthoquinone and acids.
Affected areas of the body include any parts that may directly make contact with the irritant in question. Most commonly, these are the fingers, hands, wrists, and face. Secondary spread to normally unexposed areas can complicate the clinical picture and make the diagnosis more challenging.
Confirming a diagnosis of plant-related ICD can be challenging because the various substances can irritate the skin in many different respects and to varying degrees. The frequent overlap of chemical ICD with mechanical ICD and of ICD with allergic contact dermatitis also contributes to the challenge in proper diagnosis. The presenting history, although important, may be inaccurate or incomplete, and current diagnostic tools are inadequate for confirming ICD. Other assays are on the horizon, and diagnostic techniques may improve as a better understanding of the mechanisms involved in ICD from plants is gained.
Although therapy most importantly involves the removal of the irritant, topical steroids and barrier creams are generally used as first-line therapeutic agents. The most effective preventive measures to date include avoidance and patient education.
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Dermatitis. 2009;20(2):63-78. © 2009 American Contact Dermatitis Society
Cite this: Irritant Contact Dermatitis from Plants - Medscape - Mar 01, 2009.