Cutaneous reactions to
mercury can manifest themselves in different forms. Apart from
contact dermatitis, flare-up reactions, disseminated
exanthem as well as skin symptoms in previously unaffected skin are known. Regarding systemic
allergen application, 2 separate clinical patterns, namely
acute generalized exanthematous pustulosis (AGEP) and symmetric flexural
exanthem 'baboon syndrome' have been described. Systemic
allergic reactions to
mercury are most commonly provoked by the inhalation of metallic
mercury vapours from a broken thermometer, often after previous sensitization to
mercury compounds, e.g.
Mercurochrome. Patch testing with mercurials yields positive reactions in approximately 80% of patients. We report 3 patients, 2 with flexural
exanthem, and 1 presenting with AGEP, respectively. Positive patch tests to
mercury derivatives could be demonstrated in all of them. Furthermore, non-toxic serum
mercury levels were detected in 2 of the patients. The present review provides a survey of the literature on systemic allergic
exanthem to
mercury. However, plausible explanations for the distribution pattern of the
skin manifestations in AGEP and flexural
exanthem are still lacking.