Background: Many pigmentary disorders can be manifested as linear streaks of hyperpigmentation, along theBlaschko`s line. These include progressive cribriform and zosteriform hyperpigmentation (PCZH) and linear andwhorled nevoid hyperpigmentation (LWN...
Background: Many pigmentary disorders can be manifested as linear streaks of hyperpigmentation, along theBlaschko`s line. These include progressive cribriform and zosteriform hyperpigmentation (PCZH) and linear andwhorled nevoid hyperpigmentation (LWNH). There have been debates on the universally accepted diagnostic criteriadifferentiating these disease entities.Objective: To determine the clinicopathologic characteristics of hyperpigmentation along the line of Blaschko and toexamine the acceptability of PCZH or LWNH criteria as a diagnostic tool for differentiating these diseases.Methods: A retrospective study was conducted on 13 patients who presented with linear hyperpigmentation alongthe Blaschko`s line. The patients` clinicopathologic characteristics were analyzed and matched with the PCZH/LWNH diagnostic criteria.Results: Age of onset widely ranged from birth to 61 years, but predominantly before the age of 4 years. Themale-female ratio was 1:1.2. Trunk was the most common site of involvement. Histologic examination commonlyshowed a basal layer hyperpigmentation in all patients and pigmentary incontinence was observed in 2 patients. Fourpatients who satisfied all the diagnostic criteria for PCZH also fulfilled the diagnostic criteria for LWNH, except forthe timing of onset. An additional 4 patients satisfied all the diagnostic criteria for LWNH and also fulfilled thediagnostic criteria for PCZH, except for the timing of onset. Excluding the age of onset criteria, the other 3 patientsfulfilled both diagnostic criteria for PCZH and LWNH.Conclusion: These results demonstrate that PCZH and LWNH should not be considered as a different disease entityand that supports the idea that these are part of the same disease spectrum. (Korean J Dermatol 2012;50(12):1027∼1035)