1. “Arrow” sign: A rapid microscopic diagnosis of hair change associated with epidermal growth factor receptor inhibitors 
Pai-Shan Cheng, MD, Feng-Jie Lai, MD, PhD 
Journal of the American Academy of Dermatology 
Volume 69, Issue 3, Pages (September 2013)
DOI: /j.jaad
Copyright © 2012 American Academy of Dermatology, Inc. Terms and Conditions

2. Fig 1
Epidermal growth factor receptor inhibitor–related hair and scalp change. A, Patient 1, 49-year-old woman had painful, erythematous papulopustule and plaques with crusts and hair loss over scalp after taking gefitinib 250 mg/d for 2 months. B, Plucked anagen hairs from patient 1 showed degeneration of distal part of root sheaths (red arrow) and distal split of remaining proximal part (blue arrowhead), giving “arrow” appearance microscopically. C, Scalp biopsy specimen in patient 3 showed atrophic outer root sheath (more obvious in distal third part). There is cleftlike area over outer root sheath (arrowheads), and distal part from cleft showed atrophy of outer root sheath that is compatible with findings in B (red arrow).
Journal of the American Academy of Dermatology  , DOI: ( /j.jaad )
Copyright © 2012 American Academy of Dermatology, Inc. Terms and Conditions