JEADV
LETTER TO THE EDITOR
Non-occupational allergic contact dermatitis to Dalbergia nigra Editor Contact with wood, especially exotic one, can lead to a wide variety of cutaneous manifestations,1,2 including irritant contact dermatitis (more frequent), phototoxic dermatitis and other less common situations like allergic contact dermatitis, contact urticaria, photoallergic reactions, erythema multiforme-like reactions, pigmented contact dermatitis and lymphomatoid contact dermatitis. A 47-year-old woman without history of relevant diseases suddenly developed erythemato-vesiculous well-demarcated plaques on both wrists in 4 days that required topical corticosteroids and systemic treatment. She related having worn a bracelet of tropical wood from Central America for a month (Fig. 1) on both wrists, although more frequently on the left one. This tropical wood was identified as Brazilian rosewood or Dalbergia nigra. The determination was made on the base of a xylotomist, a wood expert who cut slices of the tropical wood and compared them with reference samples. To establish the diagnosis, epicutaneous testing was performed. Results were negative for the allergens included in the basal European and Spanish series. Nevertheless, the patch test with 10% powder of their own bracelet and also Dalbergia nigra in petrolatum was strongly positive (+++) at 48 and 96 h, contrary to the 10 healthy patch tested controls who were negative (Fig. 2). Allergic contact dermatitis to wood (type IV hypersensitivity) usually comes from wood dust while working with it for a long time, causing airborne contact dermatitis that may affect the skin (also non-exposed skin, due to friction and sweating), mucous membranes and/or respiratory tract. Although allergic contact dermatitis from wood is rare, exotic wood from tropical and subtropical regions contains potent allergens (mainly quinones). Moreover, cross-reactivity among exotic woods is common, as their allergens share a similar structure.1 The benzoquinones present in Dalbergia spp are called dalbergiones and, among them, R-4-methoxydalbergione is a potent sensitizer in Dalbergia nigra. Patch tests with the patient’s own products are essential when testing for exotic woods, as standard series do not include specific allergens of these woods.2–5 Particular identification of the tropical wood allergen is a complex process, either by specialized allergen batteries or by a taxonomist on wood.6
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Hereby we present a case of allergic contact dermatitis caused by a bracelet made of Brazilian rosewood (Dalbergia nigra) out of the occupational environment, a fact scarcely reported in the literature3–5 but increasing due to the upraising distribution of exotic woods in our environment and therefore clinicians should be aware of it. We emphasize the importance of patch testing with the patient’s own product as well as using healthy controls, besides the difficulty of identifying the tropical wood allergen – which is not done regularly in the daily practice.
Figure 1 Our patient showed an allergic contact dermatitis after wearing her wooden bracelet from Central America for a month.
Figure 2 Patch test reading at 96 h with the patient’s own product.
© 2014 European Academy of Dermatology and Venereology
Letter to the Editor
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s,1,* I. Go mez-Martın,1 R.-M. Pujol,1 A. Ortiz-Brugue nez-Arnau1 T. Rustenmeyer,2 A. Gime 1 noma, Department of Dermatology, Hospital del Mar. Universitat Auto Barcelona, Spain, 2Department of Dermatology, VU University Medical Centre, Amsterdam, The Netherlands s. E-mail: ariadna.ortiz. *Correspondence: A. Ortiz Brugue
[email protected] References 1 Podjasek JO, Cook-Norris RH, Richardson DM et al. Allergic contact dermatitis from exotic woods: importance of patch-testing with patientprovided samples. Dermatitis 2011; 22: E1–E6.
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2 Correale CE, Marks JG Jr. Contact dermatitis in a woodworker. Am J Contact Dermat 2002; 13: 42–44. 3 Hausen BM. Rosewood allergy due to an arm bracelet and a recorder. Derm Beruf Umwelt 1982; 30: 189–192. 4 Dias M, Vale T. Contact dermatitis from a Dalbergia nigra bracelet. Contact Dermatitis 1992; 26: 61–62. 5 Fisher AA, Bikowski J Jr. Allergic contact dermatitis due to a wooden cross made of Dalbergia nigra. Contact Dermatitis 1981; 7: 45–46. 6 Hausen BM. Contact allergy to woods. Clin Dermatol 1986; 4: 65–76. DOI: 10.1111/jdv.12733
© 2014 European Academy of Dermatology and Venereology