Blaschkitis is a unilateral remitting and relapsing eruption of itchy inflammatory vesicles and papules (resembling eczema) that occurs usually on the trunk in adults following Blaschko’s lines. It would be difficult to distinguish from linear Grover’s disease. Blaschko's lines pattern is attributed to the lines of migration and proliferation of epidermal cells during embryogenesis. The lines do not correspond to any known nervous, vascular or lymphatic structures.
The histopathology is more eczematous (spongiotic) than lichenoid. Some have considered it to represent an adult version of lichen striatus and actually, the acronym BLAISE (Blaschko linear acquired inflammatory skin eruption) has been used to cover both. Blaschkitis (adults) is rarer, more itchy, more papulovesicular, more extensive, resolving more rapidly, and relapsing more frequently than lichen striatus (children). BLAISE is best regarded as a description rather than a diagnosis, pending identification that is more precise. Steroids may be effective.
This page was last updated in February 2015.