A clinical and patch test study in a tall-oil rosin factory.

Rosin of different sources is commonly used in many technical products and is known to cause contact allergy. The aim of the present investigation was to study the frequency of occupational dermatoses and of contact allergy to rosin in a factory producing tall-oil rosin. 163/180 present employees and 17/35 former employees participated in the study, which consisted of interview, clinical examination and patch testing with a standard series and additional rosins. 1/4 of those examined had some kind of current skin lesion. There were 10 cases of hand eczema. 7 subjects were patch-test-positive to gum rosin in the standard series. This frequency is about the same as among dermatitis patients at our clinic. Only 1 reaction to tall-oil rosin and none to the modified rosins tested were found. No relation between a positive patch test reaction to rosin and current skin disease could be established. No case of ongoing occupational skin disease was proved.