title: The itchy scalp--scratching for an explanation.
abstract: Scalp pruritus is a common complaint that is considered a diagnostically and therapeutically challenging situation. Scalp skin has a unique neural structure that contains densely innervated hair follicles and dermal vasculature. In spite of the recent advances in our understanding of itch pathophysiology, scalp itching has not been studied as yet. In this review, we summarize the current knowledge on the neurobiology of scalp and hair follicles as well as itch mediators and provide a putative mechanism for scalp itch with special emphasis on neuroanatomy and pathophysiology.
authors.affiliation: Department of Dermatology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Ghada A
authors.initials: GA
authors.lastname: Bin Saif
authors.forename: Marna E
authors.initials: ME
authors.lastname: Ericson
authors.forename: Gil
authors.initials: G
authors.lastname: Yosipovitch
mesh_terms: D000818:Animals; D006801:Humans; D011537:Pruritus / Q000188:drug therapy / Q000209:etiology* / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology*; D012535:Scalp / Q000294:innervation* / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology*; D012629:Sebum / Q000378:metabolism
references.citation: J Invest Dermatol. 2001 Feb;116(2):236-45
references.pmid: 11179999
references.citation: J Toxicol Sci. 2009 Oct;34(4):427-31
references.pmid: 19652466
references.citation: Nat Immunol. 2004 Jul;5(7):752-60
references.pmid: 15184896
references.citation: Am J Pathol. 2003 Mar;162(3):803-14
references.pmid: 12598315
references.citation: Br J Dermatol. 1993 Jun;128(6):597-605
references.pmid: 8338743
references.citation: J Burn Care Res. 2011 Jan-Feb;32(1):150-9
references.pmid: 21099694
references.citation: Nat Med. 2000 Feb;6(2):151-8
references.pmid: 10655102
references.citation: J Eur Acad Dermatol Venereol. 2011 Nov;25(11):1295-8
references.pmid: 21241375
references.citation: Dermatol Clin. 2003 Oct;21(4):629-44
references.pmid: 14717404
references.citation: J Mol Med (Berl). 2005 May;83(5):386-96
references.pmid: 15759104
references.citation: J Investig Dermatol Symp Proc. 2005 Dec;10(3):194-7
references.pmid: 16382662
references.citation: Science. 2009 Sep 18;325(5947):1531-4
references.pmid: 19661382
references.citation: Haematologica. 2009 Nov;94(11):1537-45
references.pmid: 19608683
references.citation: Arch Dermatol Res. 2002 Jul;294(4):172-7
references.pmid: 12111347
references.citation: FEMS Immunol Med Microbiol. 2008 Nov;54(2):203-14
references.pmid: 18752620
references.citation: Cell. 2001 Sep 7;106(5):619-32
references.pmid: 11551509
references.citation: Int J Dermatol. 2003 May;42(5):342-5
references.pmid: 12755968
references.citation: Trends Pharmacol Sci. 2009 Aug;30(8):411-20
references.pmid: 19608284
references.citation: Pain. 2002 Mar;96(1-2):9-12
references.pmid: 11932056
references.citation: Arch Dermatol Res. 1997 Apr;289(5):256-60
references.pmid: 9164634
references.citation: Arch Dermatol. 1998 Mar;134(3):327-30
references.pmid: 9521031
references.citation: Proc Natl Acad Sci U S A. 2009 Jul 7;106(27):11330-5
references.pmid: 19564617
references.citation: Med Mycol. 1998 Apr;36(2):97-106
references.pmid: 9776820
references.citation: J Pediatr Hematol Oncol. 2009 Dec;31(12):972-6
references.pmid: 19935099
references.citation: Br J Dermatol. 2007 Jun;156(6):1272-7
references.pmid: 17535226
references.citation: Naunyn Schmiedebergs Arch Pharmacol. 1987 Nov;336(5):538-45
references.pmid: 2449621
references.citation: Arch Dis Child. 1994 Feb;70(2):119-22
references.pmid: 8129432
references.citation: Cell Tissue Res. 2000 Oct;302(1):31-7
references.pmid: 11079713
references.citation: Br J Dermatol. 1997 Sep;137(3):415-7
references.pmid: 9349340
references.citation: Allergy. 2010 Jul;65(7):805-21
references.pmid: 20384615
references.citation: J Interferon Cytokine Res. 2004 May;24(5):271-81
references.pmid: 15153310
references.citation: Br J Dermatol. 2002 Jul;147(1):71-9
references.pmid: 12100187
references.citation: J Am Acad Dermatol. 2007 Jul;57(1):47-53
references.pmid: 17467854
references.citation: Int Arch Allergy Immunol. 2007;144(3):211-6
references.pmid: 17579279
references.citation: Arch Dermatol. 2009 Sep;145(9):1062-3
references.pmid: 19770456
references.citation: Semin Dermatol. 1992 Jun;11(2):176-82
references.pmid: 1498022
references.citation: Plast Reconstr Surg. 1989 Jun;83(6):939-45; discussion 946-7
references.pmid: 2727166
references.citation: J Invest Dermatol. 1993 Jul;101(1 Suppl):75S-81S
references.pmid: 8326156
references.citation: J Lab Clin Med. 1993 Dec;122(6):658-66
references.pmid: 8245685
references.citation: Semin Cutan Med Surg. 2011 Jun;30(2):87-92
references.pmid: 21767768
references.citation: Acta Derm Venereol. 2011 Jun;91(4):404-8
references.pmid: 21336476
references.citation: Neurosci Lett. 2011 Apr 25;494(2):165-8
references.pmid: 21396428
references.citation: Exp Dermatol. 1999 Aug;8(4):314
references.pmid: 10439244
references.citation: Int J Dermatol. 2003 Apr;42(4):260-4
references.pmid: 12694489
references.citation: Exp Dermatol. 2002 Oct;11(5):448-55
references.pmid: 12366698
references.citation: Inflamm Allergy Drug Targets. 2010 Jul;9(3):173-80
references.pmid: 20553229
references.citation: J Peripher Nerv Syst. 1999;4(1):43-52
references.pmid: 10197064
references.citation: Arch Dermatol Res. 2000 Dec;292(12):605-11
references.pmid: 11214821
references.citation: PLoS One. 2011;6(5):e20559
references.pmid: 21655234
references.citation: Hautarzt. 2000 Mar;51(3):164-72
references.pmid: 10789077
references.citation: Dermatology. 2000;200(2):93-8
references.pmid: 10773693
references.citation: Acta Derm Venereol. 2010 Jul;90(4):395-400
references.pmid: 20574605
references.citation: Am J Pathol. 2004 Jul;165(1):259-71
references.pmid: 15215181
references.citation: Nat Rev Neurosci. 2006 Jul;7(7):535-47
references.pmid: 16791143
references.citation: Semin Dermatol. 1995 Dec;14(4):326-9
references.pmid: 8679440
references.citation: Nat Neurosci. 2002 Mar;5(3):201-9
references.pmid: 11850634
references.citation: Exp Dermatol. 2008 Mar;17(3):214-27
references.pmid: 18261087
references.citation: Curr Opin Neurobiol. 2002 Aug;12(4):372-9
references.pmid: 12139983
references.citation: Contact Dermatitis. 2008 Oct;59(4):226-32
references.pmid: 18844698
references.citation: Acta Derm Venereol. 1995 Jul;75(4):300-4
references.pmid: 8578954
references.citation: Eur J Pain. 2006 Jul;10(5):473-8
references.pmid: 16678456
references.citation: Toxicol In Vitro. 1996 Dec;10(6):729-42
references.pmid: 20650257
references.citation: Physiol Behav. 1974 Dec;13(6):825-36
references.pmid: 4445288
references.citation: J Invest Dermatol. 1966 Mar;46(3):231-9
references.pmid: 5930889
references.citation: Somatosens Mot Res. 1999;16(4):291-8
references.pmid: 10632026
references.citation: J Neurochem. 2006 Dec;99(5):1338-50
references.pmid: 17064360
references.citation: J Am Acad Dermatol. 2006 Mar;54(3):527-31
references.pmid: 16488311
references.citation: Curr Allergy Asthma Rep. 2009 Jul;9(4):286-90
references.pmid: 19656475
references.citation: BMC Neurol. 2007 May 23;7:11
references.pmid: 17521436
references.citation: Br J Dermatol. 2007 Feb;156(2):241-6
references.pmid: 17223862
references.citation: Br J Dermatol. 2003 Oct;149(4):718-30
references.pmid: 14616362
references.citation: Am J Pathol. 2005 Apr;166(4):985-98
references.pmid: 15793280
references.citation: Sci Signal. 2011 Jul 12;4(181):ra45
references.pmid: 21775281
references.citation: J Pain. 2003 Aug;4(6):338-43
references.pmid: 14622691
references.citation: Contact Dermatitis. 2008 Apr;58(4):234-8
references.pmid: 18353032
references.citation: J Investig Dermatol Symp Proc. 2005 Dec;10(3):295-7
references.pmid: 16382685
references.citation: J Invest Dermatol. 2004 Aug;123(2):410-3
references.pmid: 15245445
references.citation: Exp Biol Med (Maywood). 2010 Nov;235(11):1300-5
references.pmid: 20975080
references.citation: Am J Pathol. 2007 Dec;171(6):1872-86
references.pmid: 18055548
references.citation: Nature. 2007 Aug 9;448(7154):700-3
references.pmid: 17653196
references.citation: Med Mycol. 2000 Oct;38(5):337-41
references.pmid: 11092380
references.citation: Arch Dermatol Res. 2002 Feb;293(12):614-9
references.pmid: 11875644
references.citation: J Invest Dermatol. 2009 Mar;129(3):714-22
references.pmid: 18754035
references.citation: Hautarzt. 2010 Jun;61(6):467-8, 4704, 476-7
references.pmid: 20512305
references.citation: J Histochem Cytochem. 2006 Mar;54(3):275-88
references.pmid: 16009967
references.citation: Yonsei Med J. 2010 Nov;51(6):808-22
references.pmid: 20879045
references.citation: Biol Chem. 2008 Jun;389(6):669-80
references.pmid: 18627299
references.citation: Cell. 2009 Dec 24;139(7):1353-65
references.pmid: 20004959
references.citation: J Invest Dermatol. 1970 Mar;54(3):240-7
references.pmid: 5436951
references.citation: Exp Dermatol. 2009 May;18(5):424-30
references.pmid: 19382313
references.citation: Dermatol Ther. 2008 Jul-Aug;21(4):268-78
references.pmid: 18715297
references.citation: J Neurosci. 2004 May 5;24(18):4300-12
references.pmid: 15128844
references.citation: Mediators Inflamm. 2010;2010:321494
references.pmid: 20981292
references.citation: J Dermatol Sci. 2005 Jun;38(3):177-88
references.pmid: 15927811
references.citation: J Clin Invest. 2006 May;116(5):1174-86
references.pmid: 16670758
references.citation: J Allergy Clin Immunol. 2005 Jun;115(6):1268-75
references.pmid: 15940146
references.citation: J Neurosci. 1995 Mar;15(3 Pt 1):2081-96
references.pmid: 7534343
references.citation: J Vet Med Sci. 2005 Sep;67(9):915-9
references.pmid: 16210804
references.citation: J Clin Invest. 2001 Feb;107(4):409-17
references.pmid: 11181640
references.citation: Am J Contact Dermat. 1998 Sep;9(3):170-5
references.pmid: 9744910
references.citation: J Pain. 2009 Jul;10(7):702-14
references.pmid: 19559389
references.citation: Med Mycol. 2000 Jun;38(3):239-47
references.pmid: 10892993
references.citation: Br J Dermatol. 2010 Jul;163(1):70-7
references.pmid: 20302583
references.citation: J Invest Dermatol. 2010 Apr;130(4):1023-33
references.pmid: 19907432
references.citation: Adv Lipid Res. 1991;24:1-26
references.pmid: 1763710
references.citation: Virchows Arch. 1998 Apr;432(4):363-70
references.pmid: 9565347
references.citation: Br J Dermatol. 2011 Jul;165(1):5-17
references.pmid: 21219293
references.citation: J Recept Signal Transduct Res. 2002 Feb-Nov;22(1-4):431-48
references.pmid: 12503632
references.citation: JAMA. 1977 Apr 11;237(15):1559
references.pmid: 576651
references.citation: J Invest Dermatol. 2001 Oct;117(4):977-83
references.pmid: 11676841
references.citation: Neuropeptides. 2011 Dec;45(6):417-22
references.pmid: 21893340
references.citation: J Clin Invest. 2002 Oct;110(8):1185-90
references.pmid: 12393854
references.citation: Regul Pept. 2002 Dec 31;110(1):75-83
references.pmid: 12468112
references.citation: Ann Intern Med. 1986 Dec;105(6):966
references.pmid: 3777719
references.citation: Toxicol In Vitro. 1997 Aug;11(4):365-76
references.pmid: 20654323
references.citation: Lab Invest. 1994 Jul;71(1):134-40
references.pmid: 7518880
references.citation: Exp Dermatol. 2004 Mar;13(3):129-39
references.pmid: 14987252
references.citation: J Neurosci. 2003 Jul 16;23(15):6176-80
references.pmid: 12867500
references.citation: Pharm Res. 1997 Jan;14(1):42-9
references.pmid: 9034219
references.citation: JAMA. 1987 Sep 25;258(12):1624-9
references.pmid: 3306005
references.citation: Somatosens Mot Res. 2004 Sep-Dec;21(3-4):159-75
references.pmid: 15763901
references.citation: Acta Derm Venereol. 2007;87(4):291-4
references.pmid: 17598029
references.citation: J Invest Dermatol. 2000 Jun;114(6):1108-12
references.pmid: 10844552
references.citation: Int J Dermatol. 2007 Oct;46(10):1023-6
references.pmid: 17910707
references.citation: Biol Chem. 2002 Jul-Aug;383(7-8):1075-86
references.pmid: 12437090
references.citation: J Neuroimmunol. 2005 Apr;161(1-2):87-92
references.pmid: 15748947
references.citation: Acta Derm Venereol. 2009;89(4):339-50
references.pmid: 19688144
references.citation: J Invest Dermatol. 2009 Dec;129(12):2901-5
references.pmid: 19571818
references.citation: Int Arch Allergy Immunol. 1998 May;116(1):36-9
references.pmid: 9623507
references.citation: Physiol Rev. 2001 Jan;81(1):449-494
references.pmid: 11152763
references.citation: J Pain. 2008 Jan;9(1 Suppl 1):S10-8
references.pmid: 18166461
references.citation: Br J Dermatol. 2008 Jan;158(1):130-3
references.pmid: 17986305
references.citation: J Invest Dermatol. 1959 Mar;32(3):397-411
references.pmid: 13641817
references.citation: Am Fam Physician. 2006 Oct 15;74(8):1347-54
references.pmid: 17087429
references.citation: Exp Dermatol. 2006 Mar;15(3):161-7
references.pmid: 16480423
references.citation: J Neurophysiol. 1989 Dec;62(6):1270-9
references.pmid: 2600624
references.citation: Neuroimmunomodulation. 2006;13(5-6):347-56
references.pmid: 17709957
references.citation: J Neurosci. 2011 May 18;31(20):7563-7
references.pmid: 21593341
references.citation: J Clin Anesth. 2003 May;15(3):234-9
references.pmid: 12770663
references.citation: J Allergy Clin Immunol. 2006 Feb;117(2):411-7
references.pmid: 16461142
references.citation: Lab Invest. 1997 Oct;77(4):319-32
references.pmid: 9354767
references.citation: Neuron. 2010 Mar 25;65(6):886-98
references.pmid: 20346763
references.citation: Hautarzt. 1975 Jan;26(1):6-10
references.pmid: 123235
references.citation: Dermatol Ther. 2008 Jul-Aug;21(4):238-44
references.pmid: 18715292
references.citation: Arch Physiol Biochem. 1995 May;103(2):136-48
references.pmid: 9338085
references.citation: Hautarzt. 2004 Dec;55(12):1130-6
references.pmid: 15517116
references.citation: J Cutan Pathol. 2006 Aug;33(8):559-68
references.pmid: 16919030
references.citation: Int J Dermatol. 2011 Jan;50(1):102-13
references.pmid: 21182510
references.citation: J Invest Dermatol. 1984 Aug;83(2):114-7
references.pmid: 6470514
references.citation: J Am Soc Nephrol. 2005 Dec;16(12):3742-7
references.pmid: 16251241
references.citation: J Invest Dermatol. 2007 Sep;127(9):2228-35
references.pmid: 17611580
references.citation: Biochim Biophys Acta. 2007 Aug;1772(8):1004-21
references.pmid: 17462867
references.citation: Clin Exp Dermatol. 2010 Jan;35(1):2-6
references.pmid: 19663845
references.citation: Nat Neurosci. 2011 May;14(5):595-602
references.pmid: 21460831
references.citation: J Am Acad Dermatol. 2010 Oct;63(4):680-8
references.pmid: 20462660
references.citation: Stress. 2004 Mar;7(1):39-42
references.pmid: 15204031
references.citation: Ann Dermatol Venereol. 2001 Apr;128(4):545-8
references.pmid: 11395656
references.citation: Exp Physiol. 2000 Nov;85(6):839-46
references.pmid: 11187978
references.citation: Clin Exp Dermatol. 1994 Nov;19(6):463-72
references.pmid: 7534221
references.citation: J Am Acad Dermatol. 2002 Aug;47(2):245-50
references.pmid: 12140471
references.citation: Br J Dermatol. 2010 Dec;163(6):1296-300
references.pmid: 20698851
references.citation: Drug News Perspect. 2008 Sep;21(7):369-81
references.pmid: 19259550
references.citation: Clin Cosmet Investig Dermatol. 2009 Feb 19;2:9-13
references.pmid: 21436964
references.citation: Semin Cutan Med Surg. 2009 Mar;28(1):3-10
references.pmid: 19341936
references.citation: Arch Dermatol. 2010 Aug;146(8):911-6
references.pmid: 20713829
references.citation: Acta Derm Venereol. 1996 Jul;76(4):282-6
references.pmid: 8869685
references.citation: J Invest Dermatol. 2006 Sep;126(9):1937-47
references.pmid: 16912691
references.citation: J Am Acad Dermatol. 2006 Dec;55(6):996-1002
references.pmid: 17097397
references.citation: Dev Biol. 1994 May;163(1):230-40
references.pmid: 8174779
references.citation: Int J Cosmet Sci. 2010 Jun;32(3):217-24
references.pmid: 20557579
references.citation: CNS Neurosci Ther. 2011 Dec;17(6):742-9
references.pmid: 20950328
references.citation: J Dtsch Dermatol Ges. 2011 Jun;9(6):456-63
references.pmid: 21208378
references.citation: J Neurophysiol. 2008 Oct;100(4):2062-9
references.pmid: 18562548
references.citation: AMA Arch Derm. 1957 Sep;76(3):296-323
references.pmid: 13457411
references.citation: Nat Commun. 2011 Jan 18;2:161
references.pmid: 21245842
references.citation: Br J Dermatol. 2007 Nov;157(5):922-5
references.pmid: 17725670
references.citation: Ann Dermatol. 2009 Feb;21(1):18-26
references.pmid: 20548850
references.citation: Physiol Behav. 1979 Mar;22(3):541-7
references.pmid: 461544
references.citation: Neurology. 2009 Nov 10;73(19):1605; author reply 1605-6
references.pmid: 19901257
references.citation: Arch Dermatol Res. 1995;287(6):572-80
references.pmid: 7487145
references.citation: J Pharmacol Sci. 2005 Nov;99(3):277-86
references.pmid: 16276037
references.citation: J Eur Acad Dermatol Venereol. 2008 Feb;22(2):223-8
references.pmid: 18211417
references.citation: J Comp Physiol Psychol. 1973 Sep;84(3):639-43
references.pmid: 4745828
references.citation: Anesthesiology. 1993 Sep;79(3):548-54
references.pmid: 8363081
references.citation: Clin Exp Med. 2005 Jul;5(2):43-9
references.pmid: 16096852
references.citation: J Invest Dermatol. 2010 May;130(5):1468-70
references.pmid: 20072136
references.citation: Exp Dermatol. 2006 Jan;15(1):1-13
references.pmid: 16364026
references.citation: Exp Dermatol. 2004 May;13(5):273-81
references.pmid: 15140017
references.citation: J Dermatol Sci. 1991 Mar;2(2):84-91
references.pmid: 1829629
references.citation: J Clin Microbiol. 2001 Oct;39(10):3486-90
references.pmid: 11574560
references.citation: Clin Exp Allergy. 2004 Mar;34(3):456-9
references.pmid: 15005741
references.citation: Skin Pharmacol Appl Skin Physiol. 1998 Mar-Apr;11(2):87-97
references.pmid: 9603659
references.citation: Clin Exp Immunol. 1999 Aug;117(2):237-43
references.pmid: 10444253
references.citation: Exp Dermatol. 1999 Aug;8(4):282-94
references.pmid: 10439226
references.citation: J Invest Dermatol. 2011 Aug;131(8):1605-14
references.pmid: 21593771
references.citation: Allergy. 2010 Jun 1;65(6):712-21
references.pmid: 19889120
references.citation: Nat Neurosci. 2001 Jan;4(1):72-7
references.pmid: 11135647
references.citation: Proc Natl Acad Sci U S A. 2002 Nov 12;99(23):14740-5
references.pmid: 12397184
references.citation: Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi. 1998 Nov;14(6):448-51
references.pmid: 10452087
references.citation: Acta Derm Venereol. 2011 Sep;91(5):537-40
references.pmid: 21533325
references.citation: Endocr Rev. 2005 Feb;26(1):1-43
references.pmid: 15689571
references.citation: Clin Exp Dermatol. 2004 May;29(3):273-6
references.pmid: 15115510
references.citation: Nephrol Dial Transplant. 2010 Apr;25(4):1251-7
references.pmid: 19926718
references.citation: Curr Allergy Asthma Rep. 2008 Jul;8(4):306-11
references.pmid: 18606082