A 17 year old Asian girl presented to the dermatology department with symmetrical, pigmented horizontal lines on her back. Histological examination showed only chronic eczema. The patient remarked that she had scratched her back with a long bathroom loofah to relieve intractable itching. This had caused postinflammatory pigmentation of the skin overlying her ribs and vertebral prominences, sparing the intervening areas.

G A Johnston, specialist registrar, T O Bleiker, specialist registrar, R A C Graham-Brown, consultant, department of dermatology, Leicester Royal Infirmary, Leicester LE1 5WW, UK