Aim: The purpose of the study was to describe the trichoscopic features of pseudonits and to assess the usefulness of trichoscopy in their differential diagnosis. Methods: A retrospective study was performed on those patients seen for the suspicion of head or pubic lice and who underwent trichoscopy with polarized light at ×10 magnification for a more accurate diagnosis. Forty-two patients (28 males/14 females, mean age: 34.5 years, range: 7–59) were evaluated. Results: In 30 cases, trichoscopy confirmed the suspicion of head (24 cases) or pubic (6 cases) lice, whereas in 12 cases it allowed for a final diagnosis of seborrheic dermatitis (5 cases), hair casts (3 cases), trichobacteriosis (2 cases), white piedra (1 case), and trichorrhexis nodosa (1 case), by showing different types of pseudonits. Conclusion: Hair examination using trichoscopy in routine clinical practice may provide useful information for the correct diagnosis, ranging from common head and pubic lice infestations to rarer shaft abnormalities. Differentiating pseudonits from nits is essential to make the correct diagnosis in order to prevent unnecessary treatment, anxiety, and/or embarrassment.

1.
Scott
MJ
 Jr
,
Scott
MJ
 Sr
.
Nits or not? Pseudonits—simple office diagnosis
.
JAMA
.
1980
Jun
;
243
(
22
):
2325
6
.
[PubMed]
0098-7484
2.
Rudnicka
L
,
Olszewska
M
,
Rakowska
A
,
Slowinska
M
.
Trichoscopy update 2011
.
J Dermatol Case Rep
.
2011
Dec
;
5
(
4
):
82
8
.
[PubMed]
1898-7249
3.
Miteva
M
,
Tosti
A
.
Hair and scalp dermatoscopy
.
J Am Acad Dermatol
.
2012
Nov
;
67
(
5
):
1040
8
.
[PubMed]
0190-9622
4.
Lacarrubba
F
,
Micali
G
,
Tosti
A
.
Scalp dermoscopy or trichoscopy
.
Curr Probl Dermatol
.
2015
;
47
:
21
32
.
[PubMed]
1421-5721
5.
Micali
G
,
Verzì
AE
,
Lacarrubba
F
. Alternative uses of dermatoscopy in daily clinical practice: an update. J Am Acad Dermatol.
2018
Jun 16. pii:S0190-9622(18)32143-1. doi: . [Epub ahead of print]
6.
Verzì
AE
,
Lacarrubba
F
,
Dinotta
F
,
Micali
G
.
Dermatoscopy of parasitic and infectious disorders
.
Dermatol Clin
.
2018
Oct
;
36
(
4
):
349
58
.
[PubMed]
0733-8635
7.
Amer
M
,
Helmy
A
,
Amer
A
.
Trichoscopy as a useful method to differentiate tinea capitis from alopecia areata in children at Zagazig University Hospitals
.
Int J Dermatol
.
2017
Jan
;
56
(
1
):
116
20
.
[PubMed]
0011-9059
8.
Souissi
A
,
Ben Tanfous
A
,
Azzouz
H
,
Karray
M
,
Zghal
M
,
El Euch
D
, et al.
When trichoscopy enlightens clinics
.
Int J Dermatol
.
2016
Nov
;
55
(
11
):
1278
80
.
[PubMed]
0011-9059
9.
Micali
G
,
Tedeschi
A
,
West
DP
,
Dinotta
F
,
Lacarrubba
F
.
The use of videodermatoscopy to monitor treatment of scabies and pediculosis
.
J Dermatolog Treat
.
2011
Jun
;
22
(
3
):
133
7
.
[PubMed]
0954-6634
10.
Tang
JQ
,
Ran
X
,
Ran
YP
.
Cover Image: dermoscopy in vivo for the life cycle of Phthirus pubis
.
Br J Dermatol
.
2017
Jan
;
176
(
1
):
279
.
[PubMed]
0007-0963
11.
Vázquez-Herrera
NE
,
Sharma
D
,
Aleid
NM
,
Tosti
A
.
Scalp Itch: A Systematic Review
.
Skin Appendage Disord
.
2018
Aug
;
4
(
3
):
187
99
.
[PubMed]
2296-9195
12.
Lam
M
,
Crutchfield
CE
 3rd
,
Lewis
EJ
.
Hair casts: a case of pseudonits
.
Cutis
.
1997
Nov
;
60
(
5
):
251
2
.
[PubMed]
0011-4162
13.
Zawar
V
. Photoletter to the editor: Trichomycosis (trichobacteriosis) axillaris. J Dermatol Case Rep
2011
;5(2):36-7.
14.
Bonifaz
A
,
Gómez-Daza
F
,
Paredes
V
,
Ponce
RM
.
Tinea versicolor, tinea nigra, white piedra, and black piedra
.
Clin Dermatol
.
2010
Mar
;
28
(
2
):
140
5
.
[PubMed]
0738-081X
15.
Pinheiro
AM
.
Acquired trichorrhexis nodosa in a girl: the use of trichoscopy for diagnosis
.
J Dermatolog Clin Res
.
2016
;
4
:
1064
.
16.
Albayrak
H
,
Yanik
ME
.
Dermoscopic appearance of hair casts
.
J Dermatol
.
2017
Aug
;
44
(
8
):
e182
3
.
[PubMed]
0385-2407
17.
Doche
I
,
Vincenzi
C
,
Tosti
A
.
Casts and pseudocasts
.
J Am Acad Dermatol
.
2016
Oct
;
75
(
4
):
e147
8
.
[PubMed]
0190-9622
18.
Tang
JQ
,
You
ZM
,
Yang
Q
,
Ran
YP
.
Image Gallery: dermoscopy for hair casts due to traction
.
Br J Dermatol
.
2017
Apr
;
176
(
4
):
e37
.
[PubMed]
0007-0963
19.
Almazán-Fernández
FM
,
Fernández-Crehuet Serrano
P
.
Trichomycosis axillaris dermoscopy
.
Dermatol Online J
.
2017
Jun
;
23
(
6
):
13030/qt5hp5x1kz
.
[PubMed]
1087-2108
20.
Navarrete-Dechent
C
,
Fich
F
,
Gonzalez
S
.
Trichomycosis (trichobacteriosis) capitis misdiagnosed as poliosis: the utility of dermoscopy and why it should always be done
.
J Eur Acad Dermatol Venereol
.
2017
Jun
;
31
(
6
):
e275
6
.
[PubMed]
0926-9959
21.
Zhuang
K
,
Ran
X
,
Dai
Y
,
Tang
J
,
Yang
Q
,
Pradhan
S
, et al.
An Unusual Case of White Piedra Due to Trichosporon inkin Mimicking Trichobacteriosis
.
Mycopathologia
.
2016
Dec
;
181
(
11-12
):
909
14
.
[PubMed]
0301-486X
22.
Sandoval-Tress
C
,
Arenas-Guzmán
R
,
Guzmán-Sánchez
DA
.
Hair Shaft Yellow Nodules in a Pediatric Female Patient
.
Skin Appendage Disord
.
2015
Sep
;
1
(
2
):
62
4
.
[PubMed]
2296-9195
23.
Miteva
M
,
Tosti
A
.
Dermatoscopy of hair shaft disorders
.
J Am Acad Dermatol
.
2013
Mar
;
68
(
3
):
473
81
.
[PubMed]
0190-9622
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