Most eccrine hidrocystomas are solitary, asymptomatic lesions. Multiple hidrocystomas are very rare and are probably caused by dilatation of eccrine ducts. Immunohistochemical investigations are helpful in distinguishing whether a solitary or multiple form is present. An isolated hidrocystoma can be treated by surgery or electrocautery. Multiple eccrine hidrocystomas are more difficult to treat. Topical atropine may be successful for multiple lesions. We observed a patient with more than 100 lesions associated with significant hyperhidrosis. Although several systemic drugs were used, no relief of the hyperhidrosis could be achieved. During topical administration of atropine some shrinkage of cysts was seen.