10.5826/dpc.1401a44
text/xml
2160-9381
3477
en
Elisa Cinotti
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
pigmented Demodex
Pigmented Demodex Folliculorum: A Novel Dermoscopic Finding in Brown Facial Macules
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Research Letter
2024-01-31
2023-04-27
2024-01-31
2024-02-21
e2024044
Dermatol Pract Concept
Elisa Cinotti
2024/01/31
10.5826/dpc.1401a44
e2024044
Dermatology Unit, Department of Medical, Surgical and Neurosciences, University of Siena, Siena, Italy
2160-9381
pigmented Demodex
en
e2024044
Cinotti E, Bertello M, Donelli C, et al. Super-high magnification dermoscopy can detect Demodex folliculorum. J Eur Acad Dermatol Venereol. 2023;37(1):e96-e97. DOI: 10.1111/jdv.18496. PMID: 35964306.
Pigmented Demodex Folliculorum: A Novel Dermoscopic Finding in Brown Facial Macules
https://dpcj.org/index.php/dpc/article/download/3477/2527
         Pigmented Demodex Folliculorum: A Novel
        Dermoscopic Finding in Brown Facial Macules
               Magdalena Żychowska1, Linda Tognetti2, Pietro Rubegni2, Elisa Cinotti2


1 Department of Dermatology, Institute of Medical Sciences, Medical College of Rzeszow University, Rzeszow, Poland
2 Dermatology Unit, Department of Medical, Surgical and Neurosciences, University of Siena, Siena, Italy



Key words: Demodex, demodicosis, lentigo maligna, pigmented Demodex
Citation: Żychowska M, Tognetti L, Rubegni P, Cinotti E. Pigmented Demodex Folliculorum: A Novel Dermoscopic Finding in Brown
Facial Macules. Dermatol Pract Concept. 2024;14(1):e2024044. DOI: https://doi.org/10.5826/dpc.1401a44
Accepted: August 17, 2023; Published: January 2024
Copyright: ©2024 Żychowska et al. 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.
Authorship: All authors have contributed significantly to this publication.
Corresponding Author: Magdalena Żychowska, MD, PhD, Department of Dermatology; Szopena 2 Street, 35-055 Rzeszów, Poland.
Phone: +48669422237; Fax: 178666294; e-mail: magda.zychowska@gmail.com




Introduction                                                             Case Presentation
The role of Demodex mites in dermatological conditions                   Here, we present five patients with brown facial macules, in
has not been fully elucidated yet. The mites, at low densities,          whom we observed pigmentation either of the contour or
constitute normal finding in pilosebaceous follicles in adults.          of the whole body of Demodex mites under high magnifi-
However, overproliferation of Demodex, with mites visible to             cation dermoscopy (Horus system, field of view 1.7 mm x
the naked eye as whitish scales at the base of the hair, and             1.275 mm, Figure 1). This case series includes three pa-
accompanied by erythema or subjective complaints (burning,               tients with lentigo maligna (LM), who showed under der-
itch, skin hypersensitivity or roughness), is classically defined        moscopy pigmentation of the Demodex contour (Figure 1,
as demodicosis [1]. Demodicosis may be divided into primary              A-C), and one patient with LM, who presented with multiple
(pityriasis folliculorum) and secondary forms, the latter being          ­entirely-pigmented Demodex tails protruding from hair folli-
associated with rosacea, acne, perioral dermatitis, and bleph-           cles (Figure 1, D and E). In two of the aforementioned cases,
aritis [2]. Recently, a novel entity, pigmented demodicosis              the presence of pigmented Demodex was not restricted to
(PD), has been highlighted in the literature [3]. Apart from the         the heavily pigmented part of LM, but it could be also noted
aforementioned features of demodicosis, PD manifests clini-              within the areas of regression (Figure 1, C and D). Inter-
cally with facial hyperpigmentation and shows under dermos-              estingly, we also encountered one patient with solar lentigo,
copy irregularly pigmented circles surrounding hair follicles.           in whom we observed pigmented Demodex as round dark-
    The aim of the report is to highlight a new dermoscopic              brown structures inside hair follicles (Figure 1F). Hence, the
finding, pigmented Demodex, and to outline the differences               dermoscopic finding of pigmented Demodex cannot be con-
with the recently described entity, PD.                                  sidered as specific for malignant lesions and it is probably




Research Letter | Dermatol Pract Concept. 2024;14(1):e2024044                                                                        1
Figure 1. (A, B) Super-high magnification dermoscopy of lentigo maligna (LM) showing presence of pigmented Demodex as elongated white
structures with brown contours (red arrows) inside hair follicle. In addition, non-pigmented Demodex (green arrow) was detected outside the
area of the brown facial macule (magnification x150; field of view 1.7mm); (C) LM involving the hairy scalp - pigmented Demodex protrud-
ing from the hair follicles (red arrows) (magnification x150; field of view 1.7 mm); (D) LM with numerous heavily-pigmented D­ emodex tails
(red arrows) protruding from the hair follicles (magnification x30; field of view 7.5mm); (E) Clustered, entirely pigmented, and elongated
bodies of Demodex (red arrow) within the hair follicle (magnification x150; field of view 1.7mm); (F) Solar lentigo – Demodex detected
under super-high magnification dermoscopy as round brown structures (red arrow) inside the hair follicle (magnification x150; field of view
1.7 mm).



due to abundant free pigment in the epidermis and/or hair                  PD is a recently highlighted entity, which clinically pres-
follicles that stains the mites on their surface.                      ents as facial hyperpigmentation and should be taken into
                                                                       consideration in the differential diagnosis of LM [3]. Under

Conclusions                                                            dermoscopy, PD shows irregularly pigmented circles sur-
                                                                       rounding hair follicles, while in RCM dilated follicles with
The presence of Demodex folliculorum is classically con-               Demodex mites and pigmented keratinocytes around hair
firmed by standardized skin surface biopsy (SSSB) [2].                 follicles may be observed [3]. Differentiation with melano-
Non-invasive imaging methods of use for the detection                  cytic lesions may be challenging, however, unlike LM, hair
of Demodex include (video) dermoscopy, reflectance con-                follicle obstruction with pigment should not be observed in
focal microscopy (RCM), and optical coherence tomogra-                 PD. Histopathological examination of PD reveals interface
phy [4-6]. Recently, super-high magnification dermoscopy               dermatitis and heavily pigmented melanophages in the papil-
was reported as a valuable tool for non-invasive visualiza-            lary dermis, presumably corresponding to post-­inflammatory
tion of Demodex both inside and outside hair follicles [7].            hyperpigmentation following Demodex-induced inflamma-
Whitish gelatinous protrusions from hair follicles, which              tion in dark-skinned patients [3].
correspond to Demodex tails, constitute the predominant                    We would like to emphasize that the phenomenon ob-
finding. In addition, grayish dots, scaling, and red dots may          served by us, namely presence of pigmented Demodex mites
be observed.                                                           within melanocytic and non-melanocytic facial macules,



2                                                                           Research Letter | Dermatol Pract Concept. 2024;14(1):e2024044
should be distinguished from the pigmented variant of de-            3. Bertold C, Martel P, Passeron T, Bahadoran P. Pigmented de-
modicosis, PD.                                                            modicosis presenting as lentigo maligna diagnosed by reflectance
                                                                          confocal microscopy. Br J Dermatol. 2023;188(1):149-150.
   The pigmentation within Demodex folliculorum has
                                                                          DOI: 10.1093/bjd/ljac023. PMID: 36689529.
been predominantly observed by us in LM. However, we
                                                                     4.   Köse ÖK, Borlu M. Definition of videodermoscopic features
have also encountered a case of solar lentigo with heavily                of demodicosis. Int J Dermatol. 2019;58(10):1153-1159. DOI:
pigmented Demodex inside the hair follicle. Therefore, both               10.1111/ijd.14547. PMID: 31198996.
the diagnostic significance and the origin of the pigment            5.   Longo C, Pellacani G, Ricci C, De Pacee B, argenziano G,
need further research.                                                    ­Zalaudek I. In vivo detection of Demodex folliculorum by means
                                                                           of confocal microscopy. Br J Dermatol. 2012;166(3):690-692.
                                                                           DOI: 10.1111/j.1365-2133.2011.10645.x. PMID: 21929530.
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Research Letter | Dermatol Pract Concept. 2024;14(1):e2024044                                                                           3
