Keratoacanthomas arising in association with prurigo nodules in pruritic, actinically damaged skin.

There is no known association between the development of keratoacanthomas and prurigo nodules. We report a case series of 7 patients with a long-standing history of actinic damage, pruritus, and prurigo nodularis who developed widespread keratoacanthomas within the same affected area. This was a retrospective case series assessing the clinical characteristics of patients with multiple keratoacanthomas arising in association with prurigo nodules. All 7 patients were elderly Caucasian women (mean age 79 ± 3.7 years) with actinically damaged skin and a long-standing history of widespread pruritus and prurigo nodules. All patients had histologically confirmed keratoacanthomas, or squamous cell carcinomas with the clinical appearance of a keratoacanthoma, that developed within the field of prurigo nodules. All 7 patients had a clinical response to acitretin with a decrease in the number of lesions. Four patients had an associated eczematous dermatitis and were also treated with cyclosporine with improvement in pruritus and prurigo nodules and no increase in keratoacanthomas. The retrospective design and small number of patients are limitations to this study. Our case series represents a distinct subset of elderly individuals with extensive actinic damage who we believe are predisposed to developing both prurigo nodules and keratoacanthomas.