Nevoid acanthosis nigricans: Report of four cases localized to the umbilicus.

Nevoid acanthosis nigricans is a rare, benign form of acanthosis nigricans. Of the 24 cases documented in the literature, only two are exclusively localized to the umbilicus. We present four cases of nevoid acanthosis nigricans localized to the umbilicus; in patients less than 25 years of age, with no known co-morbidities, three of whom were females.

Safety and efficacy of cetirizine versus cetirizine plus ranitidine in chronic urticaria: Double-blind randomized placebo-controlled study.

Background: First-line treatment for chronic urticaria is H1 non-sedating antihistamines. When these fail, guidelines recommend combination with H2 antihistamines.

Aim: We conducted a randomized, double-blind, placebo-controlled trial.