Collagenous and elastotic marginal plaques of the hands

SUMMARY A 49‐year‐old woman presented with an asymptomatic indurated linear plaque extending from the medial surface of the right thumb along the junction of the dorsal and palmar skin of the hand onto the lateral aspect of the index finger. The left hand showed a similar but less extensive plaque. A skin biopsy showed an acellular zone in the reticular dermis composed of thickened bundles of collagen haphazardly arranged, some perpendicular to the epidermis, admixed with elastic fibres and amorphous basophilic elastotic material. Granular calcium deposits were identified, particularly within degenerate collagen bundles. These clinical and histological features are diagnostic of collagenous and elastotic marginal plaques of the hands, a slowly progressive but largely asymptomatic condition. Actinic degeneration and chronic pressure have been proposed as aetiological agents, but our patient did not exhibit marked actinic degeneration and had no history of chronic occupational pressure.