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Exclamation
mark hair
Exclamation mark hairs are most frequently seen in people who
have alopecia areata although they can also be found in hair loss
after poisoning with thallium and occasionally in other defective
hair disorders. Exclamation mark hairs look exactly as they are
named. They develop because of focal thinning causing weak points
in the growth of a hair fiber. As an affected fiber is produced
and exposed above the skin a narrow point in the fiber gets broken
off. As the hair continues to grow the next narrow section of the
hair fiber gets exposed above the skin. Before this gets broken
the hair fiber has the shape of an exclamation mark. Stopping hair
breakage and exclamation mark hairs involves treating the cause
of the hair follicle abnormality.
Exclamation
mark hair references
- Tobin SJ.
Morphological analysis of hair follicles in alopecia areata. Microsc
Res Tech. 1997 Aug 15;38(4):443-51.
- Ihm CW,
Han JH. Diagnostic value of exclamation mark hairs. Dermatology.
1993;186(2):99-102.
- Tobin DJ,
Fenton DA, Kendall MD. Ultrastructural study of exclamation-mark
hair shafts in alopecia areata. J Cutan Pathol. 1990 Dec;17(6):348-54.
- Tobin DJ,
Fenton DA, Kendall MD. Transient defects in cortical cell differentiation
form the exclamation-mark shaft in acute alopecia areata. Ann
N Y Acad Sci. 1991 Dec 26;642:483-6.
- Messenger
AG, Slater DN, Bleehen SS. Alopecia areata: alterations in the
hair growth cycle and correlation with the follicular pathology.
Br J Dermatol. 1986 Mar;114(3):337-47.
- Keipert JA. The most common type of fractured
hair in alopecia areata in children: another cause of "black dot
disease". Australas J Dermatol. 1978 Aug;19(2):74-5.
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