Dictionary of Allergies .. Australian blackwood (Acacia melanoxylon)

Australian blackwood (Acacia melanoxylon),

Important contact sensitizer wood used for furniture, cabinet work, panelling, veneers, billiard tables, inlays etc[1]. It is also a common tree used for timber in Australia. Dermatitis from this wood is usually seen in foresters and sawmillers, with dermatitis on the face, neck, forearms, and around the waist[2. Australian blackwood is known to be an important cause of allergic contact dermatitis in Australia. Previous investigations have shown that 2,6-dimethoxy-1,4-benzoquinone and acamelin are 2 of the responsible, but weak, sensitizers. When these 2 quinones are lacking, which is occasionally found, the wood still possesses allergenic properties. Hausen BM, et al (1990) isolated and identified 4 hydroxyflavans, of which 3 proved to be allergens. Melacacidin, known to be the main constituent of these flavan derivatives in the heartwood, was isolated and its sensitizing capacity in guinea pigs determined. It showed a moderate sensitizing power. Melacacidin occurs abundantly in 125 Australian and 3 African Acacia species.

References

1. Wood-Baker R, Markos J Occupational asthma due to blackwood (Acacia Melanoxylon) Aust N Z J Med. 1997 Aug;27(4):452-3.

2. Tisley, D.A.:  Australian blackwood dermatitis 1990;23:40-61.

3. 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.