Contact Eczema Caused by True Teak (tectona Grandis). a Follow-up Study of a Previous Epidemiological Investigation, and a Study into the Sensitizing Effect of Various Teak Extracts.

A follow-up study of a previous epidemiological investigation in a furniture factory concerning allergic contact eczema caused by true teak (Tectona grandis) clearly shows that a good educational campaign associated with specific and general prophylactic measures are able to control occupational dermatoses. At the first investigation 20-5 % of the workers had allergic contact eczema and/or severe itching whereas only 83% suffered from the same complaints on re-examination. The different prophylactic measures previously recommended had been taken. Patch tests with various teak extracts were made on 13 workers sensitized to teak; these showed that lapachol (a derivative of naphthoquinone) is one of the sensitizing agents in teak wood. Furthermore, allergic reactions were obtained in seven of these workers when Jacaranda wood dust containing lapachol was used as the test substance.