Ainhum Workup

Updated: May 02, 2017
  • Author: Jeannette Rachel Jakus, MD, MBA; Chief Editor: Dirk M Elston, MD  more...
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Imaging Studies

The radiographic manifestations of ainhum are diagnostic. [18, 19]  Initially, a radiolucent band can be observed constricting the base of the involved toe, with distal swelling. Osteolysis develops in the distal and middle phalanges, with a characteristic tapering effect. Ultimately, the bone narrows until it fractures and autoamputates.

The radiographic appearances in pseudoainhum are similar or identical to true ainhum.


Histologic Findings

Histologically, ainhum shows fissuring and epidermal hyperkeratosis and parakeratosis, which is followed by a fibrotic reaction under the deepening fissure. The fibrosis is predominately composed of collagen. As scar tissue contracts, it constricts and narrows neurovascular bundles. Histologic appearances in pseudoainhum are similar or identical to those observed in true ainhum.