Flag sign is seen in ___________

In kwashiorkor, the hair is straight and hypopigmented. The length of hair that grows during the period of nutritional deprivation appears reddish brown. During the phases of better nutrition, the growing pa of hair gets appropriately pigmented. This gives the appearance of alternate bands of hypopigmented and normally pigmented hair known as flag sign. Ref: Page 105; Ghai essential pediatrics; 6th edition