Keratoacanthomas Induced by Cat Scratches in an Elderly Woman

Background: Keratoacanthomas (KAs) are relatively common self-limited squamous proliferations. It is a matter of debate, whether they are a variant of squamous cell carcinoma or benign neoplasms. The exact etiology is uncertain, but is believed to be multifactorial, and is reportedly associated with trauma. This report describes an elderly woman with multiple keratoacanthomas developing at sites scratched by a pet cat. Methods: A case of a 92-year-old woman with Alzheimer’s disease, presented with multiple rapidly growing, bizarre looking lesions on the left leg. The lesions appeared several weeks after being scratched by a cat. Results: Tissue cultures for bacteria, fungi and atypical mycobacteria were negative. Histopathologic examination was consistent with keratoacanthoma. Conclusion: The development of Keratoacanthomas (KAs) have been associated with actinic damage, genetic susceptibility, carcinogens, immunosuppression and viruses. It also seems that keratoacanthoma has predilection for sites with previous trauma. Our case is a further evidence that trauma and keratoacanthoma are closely related.