Blackwood

Author: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, 1999.

Common name:	Australian Blackwood, Wattle or Acacia.
Botanical name:	Acacia melanoxylon
Family:	Leguminosae
Origin:	Native to south-eastern Australia.
Description:	An evergreen wattle with dense foliage, balls of cream flowers and twisted pods. Height: 20 m.

Uses	Gum arabic, derived from acacia (usually A. senegal), is used in the printing trade, and as a binding agent in the making of some medications. Gum arabic is also commonly used as a food additive. Because of its excellent timber properties, Australian blackwoods are increasingly being planted in New Zealand. Blackwood is used in making furniture, boats, musical instruments, etc.
Allergens	The allergens appear to be 2,6-dimethoxy-1,4-benzoquinone, acamelin, and melacacidin (in heartwood).
Allergy	Hand dermatitis has been reported after contact with both the wood and gum arabic. Sawdust is a problem, particularly in furniture makers. Hayfever, rhinitis, conjunctivitis and other respiratory problems are of increasing concern. The prevalence of allergy to acacias, as shown in a number of Australian and Asian studies, is increasing.
Cross-reactions	Meranti (Shorea spp.) and some kinds of Mahogany.
Other information
Patch test

References

Baratawidjaja IR, Baratawidjaja PP, Darwis A, et al. Prevalence of allergic sensitization to regional inhalants among allergic patients in Jakarta, Indonesia. Asian Pac J Allergy Immunol 1999 Mar;17(1):9–12. PubMed
Sam CK, Kesavan-Padmaja, Liam CK, et al. A study of pollen prevalence in relation to pollen allergy in Malaysian asthmatics. Asian Pac J Allergy Immunol 1998 Mar;16(1):1–4. PubMed
Wood-Baker R, Markos J. Occupational asthma due to blackwood (Acacia Melanoxylon). Aust N Z J Med 1997 Aug;27(4):452–3. PubMed
De Zotti R, Gubian F. Asthma and rhinitis in wooding workers. Allergy Asthma Proc 1996 Jul-Aug;17(4):199–203. PubMed
Correia O, Barros MA, Mesquita-Guimaraes J. Airborne contact dermatitis from the woods Acacia melanoxylon and Entandophragma cylindricum. Contact Dermatitis 1992 Nov;27(5):343–4. PubMed
Ariano R, Panzani RC, Amedeo J. Pollen allergy to mimosa (Acacia floribunda) in a Mediterranean area: an occupational disease. Ann Allergy 1991 Mar;66(3):253–6. PubMed
Hausen BM, Bruhn G, Tilsley DA. Contact allergy to Australian blackwood (Acacia melanoxylon R.Br.): isolation and identification of new hydroxyflavan sensitizers. Contact Dermatitis 1990 Jul;23(1):33–9. PubMed
Clarke PS. Allergic reactions to blackwood (Acacia melanoxylon). Med J Aust 1989 Feb 20;150(4):222–3. PubMed
Anderson DM. Evidence for the safety of gum arabic (Acacia senegal (L.) Willd.) as a food additive--a brief review. Food Addit Contam 1986 Jul-Sep;3(3):225–3. PubMed
Howlett BJ, Hill DJ, Knox RB. Cross-reactivity between Acacia (wattle) and rye grass pollen allergens. Detection of allergens in Acacia (wattle) pollen. Clin Allergy 1982 May;12(3):259–68. PubMed
Lovell CR.1993, Plants and the Skin, Blackwell, Oxford.
Mitchell JC, Rook A, 1979, Botanical Dermatology, Plants and Plant products injurious to the skin, Greengrass, Vancouver.

Blackwood

References

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