Introduction to contact dermatitis
Robin Lewallen, Adele Clark, Steven R. Feldman in Clinical Handbook of Contact Dermatitis, 2014
The list of allergens that cause ACD continues to grow. There are over 3,500 environmental contact allergens reported in the literature.5 Exposure to a particular allergen can occur for years before developing a delayed hypersensitivity immune response. After sensitization occurs, subsequent exposure to the allergen may result in ACD even if used in small concentrations.6 Poison ivy (urushiol) is another common allergen but is not included in typical testing or in the frequency results by the North American Contact Dermatitis Group (NACDG). Topical medications are a common cause of contact dermatitis, including antibiotics (58%), corticosteroids (30%), and anesthetics (6%). This generates a conundrum when selecting treatments for contact dermatitis, as upwards of 30% of patients with a medication allergy had a positive patch test to a topical corticosteroid, either the steroid or the vehicle.7 Many of the products that are used on a daily basis contain one or more potential allergens (Table 1.2).
Personal Protective Equipment (PPE): Practical and Theoretical Considerations
Brian J. Lukey, James A. Romano, Salem Harry in Chemical Warfare Agents, 2019
Incidentally, SERPACWA superbly protects skin against the irritating effects of urushiol (the active ingredient in both poison ivy and poison oak), and this was proved in tests conducted by the military employing human beings. Since it is unethical to conduct tests that expose human beings to CWAs, the active ingredient of these previously mentioned materials was substituted. The military owns the patent rights to SERPACWA. In the future, in an effort to recoup development costs, they may license it for commercial development for use against urushiol-containing irritants. Lukey et al. provide a far more extensive review of protective skin creams in Chapter 25.
Poison Ivy/Oak/Sumac
Charles Theisler in Adjuvant Medical Care, 2023
Poison ivy, oak, and sumac are common poisonous plants on the North American continent. When these plants are touched, they deposit an oily sap called urushiol onto the skin. The sap is noted for its ability to create a localized type of allergic contact dermatitis with an uncomfortable, red, itchy, blistery rash. Poison ivy, oak, and sumac rashes are not contagious and cannot spread from one person to another even if there are open sores, because blister fluid does not contain urushiol. Only if another person touches the urushiol that is still on the affected person or his or her clothing can the rash be acquired.
Himalayan poisonous plants for traditional healings and protection from viral attack: a comprehensive review
Published in Toxin Reviews, 2022
Shriya Pathania, Diksha Pathania, Priyanka Chauhan, Mamta Sharma
Hay fever caused by pollen from ragweed, birch, hazel, timothy grass, and ryegrass is the common case of phytoallergy. Urticaria resulting from eating strawberries and allergy to peanuts are some other recognized allergy conditions due to phytoconstituents. Some phytoconstituents cause certain forms of extrinsic allergic alveolitis. Pyrethrum allergy is a known problem on the plantations of Chrysanthemum cineriaefolium in many countries. The Japanese cedar (Cryptomeria japonica) is a source of annual misery because of the massive amounts of highly allergenic pollen every spring (Wink and Van Wyk 2008). A Phytoallergic problem has increased greatly in recent decades. A different allergic mechanism occurs in regions with poison ivy (Rhus toxicodendron, T. rydbergii), poison oak (Rhus juglandifolia) and poison sumac (Rhus vernix). The active ingredient is urushiol. Its first exposer of sap to the skin has no noticeable clinical effect. Urushiol acts as a hapten, however. It binds to proteins in the skin, creating new epitopes. Upon subsequent contact pronounced pruritic dermatitis develops (Wink 2010).
Bioactivation of herbal constituents: mechanisms and toxicological relevance
Published in Drug Metabolism Reviews, 2019
Bo Wen, Peter Gorycki
Urushiol (Figure 11(h)), a pale-yellow oily mixture of catechols with an alkyl side chain, are the allergenic components of Toxicodendron radicans (poison ivy) and Toxicodendron diversilobum (poison oak). Brushing up against these plants results in allergic contact dermatitis, leading to an itchy rash. Oxidation of urushiols to ortho-quinones likely results in depletion of intracellular GSH and covalent modification of macromolecules leading to skin toxicity (Dunn et al. 1982). Urushiol-induced contact dermatitis is known to be mediated by T lymphocytes that recognize urushiol-bound proteins as an antigen (Dunn et al. 1982). Urushiol ortho-quinones and/or ROS production are likely also responsible for the DNA fragmentation observed in human cancer cells treated with urushiol leading to induction of apoptosis (Kim et al. 2013).
Clinical and immunologic differences in cellulitis vs. pseudocellulitis
Published in Expert Review of Clinical Immunology, 2021
Michael Goldenberg, Henry Wang, Trent Walker, Benjamin H Kaffenberger
Allergic contact dermatitis (ACD) is a delayed type IV hypersensitivity reaction resulting from allergen-specific T cell activation [50]. When it is misdiagnosed as cellulitis, it is most often related to abrupt exuberant exposure such as plant dermatitis, ultraviolet light exposure, or paraphenylenediamine in hair dye. It is extremely unlikely for a rinse-off product like shampoo, detergents, or soaps to cause an abrupt reaction that could be confused with cellulitis. This condition typically starts with extensive itching, redness, microvesiculations in the skin, and develops into large bullae if severe. The presence of itch is often a distinguishing factor. In addition, linear streaks, scattered black dots (presence in urushiol-related dermatitis from poison ivy), and geometric patterns should help clinically differentiate patients.
Related Knowledge Centers
- Organic Compound
- Toxicodendron
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- Toxicodendron Radicans
- Toxicodendron Vernix
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- Urushiol-Induced Contact Dermatitis