Occupational cobalt induced systemic contact dermatitis

ARTICLE

Auteur(s) : Yukie Asano, Teruhiko Makino, Osamu Norisugi, Tadamichi Shimizu

Department of Dermatology, Graduate School of Medicine, University of Toyama, 2630 sugitani, Toyama, Toyama 930-0194, Japan

Systemic contact dermatitis occurs with drugs, foods and dental metals including nickel and chromate [1]. However, contact with a hard-metal powder in the workplace is a rare cause. In particular, there has been no previous report of occupational cobalt-induced systemic contact dermatitis, which we describe here.

A 19-year-old male presented to the clinic for evaluation of lesions which had developed on his hands and, thereafter, progressed to a generalized eczematous eruption with itching. The lesions on his arms, chest and back consisted of papules and edematous erythemas (figure 1). There were no oral symptoms. He had no history of atopic dermatitis or any previously known allergic contact dermatitis. His symptoms developed 2 to 4 weeks after he started working as a grinder in a hard-metal factory. Hard metal is manufactured by a powder metallurgical process in which about 90% tungsten carbide, small amounts of other metal carbides and polyethylene glycol are mixed with about 10% metallic cobalt.

A skin biopsy from the right lower abdomen showed a lymphocyte infiltration and dilated vessels in the upper dermis. Patch testing was performed with the M-17 metal series (Torii Pharmaceutical Co., Ltd.; Tokyo, Japan), and the hard-metal powder which he usually worked with. The results showed positive reactions for 1.0% cobalt chloride in petroleum, 5% nickel sulfate in petroleum and the metal powder in petroleum. Furthermore, his symptoms improved after treatment with topical corticosteroids and oral anti-histamine H1 blockers, however, they immediately recurred not only on his face and arms but also on his chest and back which were protected against metal dust by his clothes when he entered the workplace, in spite of the fact that he did not touch any metals. Therefore, this case was diagnosed as systemic contact dermatitis to cobalt. Nickel was excluded as a potential cause because the metal the patient came in contact with did not contain nickel. By changing his workplace, the patient’s systemic contact dermatitis disappeared.

Generally, contact dermatitis is produced by external exposure of the skin to an allergen, but sometimes a systemically administered allergen may reach the skin through the circulatory system and thereby produce systemic contact dermatitis [1]. The occurrence of localized contact dermatitis due to an occupational exposure to cobalt in the hard metal industry has been reported [2-5]. However, to our knowledge, no previous case of systemic contact dermatitis from such exposure has been reported. Previous studies have reported that exposure to cobalt is not sufficient to induce an allergy [6]. Therefore, other skin diseases or factors which damage the skin seem to be a prerequisite for the cobalt allergy. Hand grinding usually has a more traumatic effect on the hands than other activities in hard-metal work, which was the case in the current patient, who initially presented with irritant hand dermatitis. The systemic dermatitis was most likely triggered by airborne contact through the inhalation of cobalt.

Acknowledgements

References

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6 Fischer T, Rystedt I. Cobalt allergy in hard metal workers. Contact Dermatitis 1983; 9: 115-21.