Acute calcific periarthritis in a child.

We wish to present an account of a child who developed acute calcification in his thenar eminence to highlight the difficulty in differentiation between calcific periarthritis, acute infection, on clinical grounds. Calcific periarthritis is due to hydroxyapatite crystal deposits in bursae, tendons and ligaments (Bonavita 1980) with characteristic radiographic appearances of opacities of variable density and shape around joints (Hitchcock 1959). The condition was first described in the shoulder, by Duplay in 1870 (Sandstrom 1938) and this remains the most commonly affected site. The hip, elbow, wrist, knee and ankle may also be involved but involvement of the hand is uncommon. Involvement in this site was first described in 1924 by Cohen (Carroll 1955). The previously reported age span ranged from thirteen years upwards, with an average of forty-five years, both sexes being equally affected (Currey 1970, Hitchcock 1959, Bonavita 1980).