Terra firma-forme dermatosis: Differential diagnosis and response to salicylic acid therapy.

Terra firma-forme dermatosis (TFFD), first described by Duncan in 1987, is a relatively common but probably underdiagnosed condition, characterized by a reticular hyperpigmented dirtlike eruption resistant to washing with common soap but typically removed with rubbing with 70% isopropyl alcohol. We present a case of TFFD in an 8-year-old boy with rapid response to 5% salicylic acid in petrolatum ointment.