Use of topical ephedrine and naphazoline in the treatment of a keratoacanthoma: two case reports.

Keratoacanthoma(KA) is a relatively common low-grade malignant keratinocytic neoplasm, usually involving sun exposed areas. Up to date the etiopathogenesis of KA is not completely understood, although it is assumed that the lesion is derived from the hair follicle and that several chemical and non-chemical factors(as chemical carcinogens, mineral oil, cigarettes, trauma and immunosuppres-sion) may be implicated [1,2]. KA presents three distinct stages, characterized in a rapid proliferative phase(6-8 weeks) [3,4], a phase of stop growing [5,6] and a third stage (or involution stage) where 50% of KA undergo to spontaneous resolution in 4–6 weeks, leaving an atrophic and hypopigmented scar [7]. The typical clinical specificity and natural course of the lesion, in some cases does not require a surgical treatment and histological examination, favoring a non-invasive treatment of the lesion.