Discoid lupus erythematosus at a site of previous injury.

A 71-year-old man with three patches of discoid lupus erythematosus (DLE) confined to the right preauricular region drew our attention because of the unusual linear arrangement of the lesions. Twenty-five years previously, the patient had suffered a trauma in the same area from falling off his motorcycle. We believe that, despite the great lapse in time, this injury may have facilitated the onset of DLE in the very same area, through long-term destabilization of the local neuroimmune network. The case fits the recently coined concept of the immunocompromised district, a cutaneous region with altered immune control, more susceptible to harbouring opportunistic infections, tumours, and immune disorders.