Introduction: Perforating verruciform collagenoma, first described in 1963, designates papular and keratotic post-trauma lesions which show an aspect of epidermal perforation microscopically with large fragments of collagen issuing through fistulous chimneys, more or less pycnotic polynuclears and squamating or necrotic epidermal cells. Three publications have presented this diagnosis.
Case report: We observed a patient with multiple lesions with macroscopic and microscopic presentations suggestive of perforating verruciform collagenoma. The lesions appeared after scratches and inoculation with calcium chloride.
Discussion: This case is similar to those observed after intradermal inoculation of calcium salts. In the 4 previous cases, perforating verruciform collagenoma was associated with trauma allowing the intradermal penetration of a particular foreign material (glass wool, vegetable debris, drugs or intravenous injections, wound caused by a metallic garbage bin). The exceptional nature of perforating verruciform collagenoma in highly frequent skin wounds would suggest that a very particular post-trauma process is occurring caused by the introduction of an exogenous substance within the derma: calcium chloride in our case, a non-specific material in the four previous cases.