10.5826/dpc.1304a240
text/xml
2160-9381
3397
en
Ahu Yorulmaz
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
pseudopitting
Dermoscopy Reveals Pseudopitting of the Nail in Psoriasis 
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Research Letter
2023-10-31
2023-04-05
2023-10-31
2024-01-15
e2023240
Dermatol Pract Concept
Ahu Yorulmaz
2023/10/31
10.5826/dpc.1304a240
e2023240
Ankara Bilkent City Hospital, Department of Dermatology, Ankara, Turkey
2160-9381
pseudopitting
en
e2023240
Yorulmaz A, Aksoy GG. Dermoscopic Features of Nail Psoriasis: Revisited. Skin Appendage Disord. 2022;8(5):389-398.
Dermoscopy Reveals Pseudopitting of the Nail in Psoriasis 
https://dpcj.org/index.php/dpc/article/download/3397/2365
                      Dermoscopy Reveals Pseudopitting
                           of the Nail in Psoriasis
                                                          Ahu Yorulmaz1


1 Ankara Bilkent City Hospital, Department of Dermatology, Ankara, Turkey



Key words: dermoscopy, nail psoriasis, salmon patches, pitting, pseudopitting
Citation: Yorulmaz A. Dermoscopy Reveals Pseudopitting of the Nail in Psoriasis. Dermatol Pract Concept. 2023;13(4):e2023240. DOI:
https://doi.org/10.5826/dpc.1304a240
Accepted: May 8, 2023; Published: October 2023
Copyright: ©2023 Yorulmaz. This is an open-access article distributed under the terms of the Creative Commons Attribution-
NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use,
distribution, and reproduction in any medium, provided the original authors and source are credited.
Funding: None.
Competing Interests: None.
Corresponding Author: Ahu Yorulmaz, Ankara Bilkent City Hospital, Department of Dermatology, Ankara, Turkey. Telephone: +90 312
552 60 00 Email: ahuyor©gmail.com




Introduction                                                           patients were >10, except for one patient (case #4). Three
                                                                       patients had severe NP with a nail psoriasis severity index
Nail involvement in psoriasis is very common, with a re-               (NAPSI) score >50, whereas one patient had moderate NP
ported lifetime incidence of up to 90% in all psoriatic [1].           with an NAPSI score >25. Figures 1 and 2 show dermoscopic
Despite their high frequencies, nail alterations are usually           images of the patients.
neglected in psoriasis [2]. However, findings of nail psoriasis
(NP) are usually specific, which allows a clinical diagnosis of
psoriasis even if cutaneous lesions are absent [3]. Di Chiac-          Conclusions
chio et al described a unique manifestation of NP, which they
                                                                       Nail bed-related findings are the characterizing features of
called pseudopitting. They presented a patient with psoria-
                                                                       NP because a significant component of the pathogenesis of
sis, in whom pits were seen only above salmon patches (SP)
                                                                       psoriasis is driven through inflammatory angiogenesis [4].
[2]. Herein, cases of 3 patients with dermoscopic images of
                                                                       Cases presented here share a similar clinical appearance, in
pseudopitting and a description of other features related to
                                                                       which various nail bed-related findings are accompanied
pseudopitting are presented.
                                                                       by pseudopitting or pitting. The image of case #4 does not
                                                                       demonstrate pseudopitting but gives an idea about the evolu-

Case Presentation                                                      tion of pseudopitting. Several pits with salmon-colored cen-
                                                                       ters are located on the distal nail, which implies that these
Some descriptive epidemiologic features were observed                  pits and SP represent different stages of a spectrum of the
among the patients, including male predominance and a                  same pathological process, having different presentations
high frequency of accompanying arthritis (Table 1). One pa-            based on their location (Figure 2B). SP is the counterpart of
tient (case #2), without arthritis, had a shorter duration of          a psoriatic plaque in the nail bed, which results from focal
psoriasis. The psoriasis area and severity index scores of the         nail bed parakeratosis. SP is a pathognomonic sign, whereas




Research Letter | Dermatol Pract Concept. 2023;13(4):e2023240                                                                        1
                               Table 1. Demographic and clinical profile of the patients
        Characteristics                    Case #1                     Case #2                    Case #3                    Case #4
 Age (years)                        37                         61                         25                         36
 Sex                                M                          M                          M                          F
 Family history                     P                          A                          A                          P
 Psoriasis duration (years)         20                         1                          20                         30
 Accompanying arthritis             P                          A                          P                          P
 Previous treatments                Mtx, PhT                   PhT                        Mtx, PhT                   Mtx, biologics
 PASI                               14.7                       11.6                       15                         5.1
 Total number of affected           8/6                        10/6                       8/5                        10/4
 nails (F/T)ª
 NAPSI                              51                         66                         35                         63
 Nail findings                      DO, SP, RSL, LE,           DO, DHC, DBC, LE,          SH, SP, nail bed red       DO, SP, SH, LE,
                                    pitting                    SP, MWD, pitting           spots, DBC, LE,            DBC, nail bed red
                                                                                          pitting                    spots, pitting
 Current treatment                  Mtx                        PhT                        Mtx                        Biologic

A = absent; DBC = dilated nail bed capillaries; DHC = dilated hyponychial capillaries; DO = distal onycholysis; ªF/T =fingernail/toenail;
LE = longitudinal erythema of the nail bed; Mtx = methotrexate; MWD =multiple white dots; PASI = Psoriasis Area and Severity Index;
PhT = Phototherapy; NAPSI = Nail Psoriasis Severity Index; RSL = red spot lunula; SH = splinter hemorrhages; SP = salmon patches.




Figure 1. (A-I) Pits over SP (red lines), note peripheral white halos around some of the pits (A,C,E,F,H,I), SP with peripheral white halo (blue
lines); nail bed red spots (green rectangles). (D) A pit over a RSL (purple line). (G): Note three zones of colors in SP (orange in the center,
white in the middle and red in the outermost) (A-D, case #1; E-H, case #2, I, case #3).




pitting, which occurs due to the foci of parakeratosis in the             They suggested that pseudopitting shares similar pathogen-
nail matrix, is a very characteristic but not a specific sign             esis with pitting except for the defect of the location, which
of NP [1].                                                                causes nail plate depression [2]. Not only the underlying
    Di Chiacchio et al demonstrated full-thickness para-                  causes but also the implications of pseudopitting are being
keratosis of the nail plate over the nail bed in their patient.           questioned. Does the presence of pseudopitting signify other




2                                                                             Research Letter | Dermatol Pract Concept. 2023;13(4):e2023240
                                                                          meanings, such as having a more severe NP? Why did the
                                                                          patient of Di Chiacchio et al only manifest with pits over SP
                                                                          and not elsewhere on the nail plate? Why patients do pres-
                                                                          ent herein manifest with both pitting and pseudopitting? Do
                                                                          we fail to notice pseudopitting in everyday practice? These
                                                                          questions are unanswered yet; however, pseudopitting is ob-
                                                                          viously a pathognomonic finding of NP, which we should
                                                                          look for.


                                                                          References
                                                                           1. Haneke E. Nail psoriasis: clinical features, pathogenesis, differ-
                                                                              ential diagnoses, and management. Psoriasis (Auckl). 2017;7:51-
                                                                              63. DOI: 10.2147/PTT.S126281. PMID: 29387608. PMCID:
                                                                              PMC5774607.
                                                                           2. Di Chiacchio N, André J, Haneke E, Di Chiacchio NG, Fonseca
                                                                              Noriega L, Ocampo-Garza J. Pseudo-pitting of the nail in psoria-
                                                                              sis. J Eur Acad Dermatol Venereol. 2017;31(7):e347-e348. DOI:
                                                                              10.1111/jdv.14141. Epub 2017 Mar 1. PMID: 28129473.
                                                                           3. Yorulmaz A. Dermoscopy: the ultimate tool for diagnosis of
                                                                              nail psoriasis? A review of the diagnostic utility of dermoscopy
Figure 2. (A) Case #2: pits over SP (red lines); a white dot with a           in nail psoriasis. Acta Dermatovenerol Alp Pannonica Adriat.
peripheral white halo (green line); (B) Case#4: multiple pits on ony-         2023;32(1):11-15. PMID: 36945761.
cholytic nail plate, note central salmon color and surrounding white       4. Yorulmaz A, Aksoy GG. Dermoscopic Features of Nail Psoria-
rims (yellow triangle); SP (blue line); a wide SP on the lateral region       sis: Revisited. Skin Appendage Disord. 2022;8(5):389-398. DOI:
of the nail plate (blue star); DO with peripheral erythema (red star);        10.1159/000524109. PMID: 36161089. PMCID: PMC9485950.
nail bed red spots with peripheral white halos (green rectangle);
white patchy areas without central erythema (turquoise rectangle),
note the lesions, which embody the characteristics of both a pit and
a SP (turquoise circle).




Research Letter | Dermatol Pract Concept. 2023;13(4):e2023240                                                                                 3
