Monoline argon laser (514 nm) treatment of benign pigmented lesions with long pulse lengths.

A dichroic filter was adjusted in order to make use of the green line of an argon laser for the treatment of pigmented lesions (actinic and senile lentigo, ephelis, café-au-lait marks and spilus nevus). Using a power of 1.5 W, a spot size of 0.5 mm and pulse lengths of 200 or 300 ms, satisfactory elimination of 620 pigmented cutaneous lesions was achieved. Although the pulse lengths used were much longer than the thermal relaxation time of the melanosomes, the histology after treatment showed little damage of adjacent structures. Good restoration of the epidermis and a return of normal pigmentation led to excellent cosmetic results, with few complications.