Sometimes these are familial; usually they are not.
Trauma seems not to be important.
Fibromatous and hyperkeratotic areas appear on the backs of many finger joints, usually beginning in late childhood and persisting thereafter. There may be an association with Dupuytren’s contracture.
Occupational callosities, granuloma annulare and viral warts should be considered.
A biopsy may be helpful in the few cases of genuine clinical difficulty.
None, including surgery, is satisfactory.