Pigment bands

Dermoscopic Description
On the skin, pigment bands are used to describe multiple, yellow-brown, elongated, structures. They may be straight or curved or branching into a coral-like pattern. The lines are often parallel. In descriptive terminology, pigment bands are referred to as thick parallel lines. Pigment bands is sometimes used to describe linear pigmentation streaks seen in longitudinal melanonychia (melanonychia striata) of nails.

Lesions in which the structures arise
On the body, pigment bands are seen in some thin seborrhoeic keratoses (as they thicken, pigment bands evolve into gyri and sulci). In nails, pigment bands denote longitudinal streaks of pigment of the nail apparatus. These may be due to melanocytic activation (e.g. lentigo, trauma, drug-induced or racial melanonychia), melanocytic hyperplasia (e.g. naevus or melanoma), or other structures e.g. blood (splinter haemorrhage) or fungus. Less commonly they are due to keratinocytic lesions (e.g. onychopapilloma, Bowen’s disease, subungual seborrheic keratosis, or SCC) .