Cobalt allergy in hard metal workers

Abstract

Hard metal contains about 10% cobalt. 853 hard metal workers were examined and patch tested with substances from their environment. Initial patch tests with 1% cobalt chloride showed 62 positive reactions. By means of secondary serial dilution tests, allergic reactions to cobalt were reproduced in 9 men and 30 women. Weak reactions could not normally be reproduced. A history of hand eczema was found in 36 of the 39 individuals with reproducible positive test reactions to cobalt, while 21 of 23 with a positive initial patch test but negative serial dilution test had never had any skin problems. Hand etching and hand grinding, mainly female activities and traumatic to the hands, were found to involve the greatest risk of cobalt sensitization. 24 individuals had an isolated cobalt allergy. They had probably been sensitized by hard metal work, while the individuals, all women, who had simultaneous nickel allergy had probably been sensitized to nickel before their employment and then became sensitized to cobalt by hard metal work. A traumatic occupation, which causes irritant contact dermatitis and/or a previous contact allergy or atopy is probably a prerequisite for the development of cobalt allergy.

Prevalence of nickel and cobalt allergy among female patients with dermatitis before and after Danish government regulation: A 23-year retrospective study

“…It has previously been showed that isolated cobalt allergy is mainly observed among hard metal workers and among painters in the glass and pottery industries. 41,42 The explanation for the increasing prevalence of isolated cobalt allergy among older patients is uncertain and could be coincidental. However, the replacement of cobalt aluminate with cobalt zinc silicate (a dye less likely to release cobalt) in the blue underglaze dyes used for pottery and porcelain painting in Denmark in the 1980s may be of some relevance.…”

Hard Metal Lung Disease Diagnosed on a Transbronchial Lung Biopsy Following Recurrent Contact Dermatitis

“…Exposure to hard metals has been reported to cause other diseases in addition to HMLD, including bronchial asthma and contact dermatitis (2,3). However, to our knowledge, very few studies have reported that these diseases coexist in patients with HMLD (4).…”

Mechanisms of immunosensitization to metals (IUPAC Technical Report)

“…An allergic dermatitis has been observed in Finnish potters handling Co clay [45]. The dermatitis is of an erythematous maculopapular type [47] and is strongly associated with a history of eczema [48]. Many patients with Ni 2+ sensitivity also have Co 2+ sensitivity, but this may reflect concomitant sensitization rather than cross-reactivity.…”