Dermatology: Practical and Conceptual Observation | Dermatol Pract Concept 2017;7(1):6 35 DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Case Report A 34-year-old male patient with no relevant medical history presented at the hospital with facial erythema and desquama- tion accompanied by a pruritic sensation that had appeared two years before. He had been treated with topical corticoste- roids and pure aloe vera for a long time. Physical examination revealed facial keratotic scaly changes with a faint erythema- tous background on both cheeks and the frontotemporal area (Figures 1,2). At polarized-light dermoscopy, Demodex tails and Demodex follicular openings, erythema and non-specific scales were observed (Figures 3, 4, 5). We performed a cyano- acrylate standardized skin surface biopsy (SSSB) in the cheek involved, and the microscopic examination confirmed the presence of multiple viable Demodex mites (Figure 6). Topical steroids were tapered, and aloe vera was discontinued. The patient was given ivermectin 1% cream at night, and a sig- nificant improvement was seen after two weeks (Figures 7, 8). Based on the clinical presentation, positive SSSB examination, and positive response to anti-Demodex therapy, we concluded this was a case of topical steroid induced-demodicosis. Comments Human demodicosis (DD) is a skin disease of the pilose- baceous units associated with human Demodex, a widely Usefulness of dermoscopy in the diagnosis and monitoring treatment of demodicidosis Paula Friedman1, Emilia Cohen Sabban 1, Horacio Cabo 1 1 Dermatology Department, Instituto de Investigaciones Médicas “A. Lanari”, University of Buenos Aires, Argentina Key words: dermoscopy, demodicidosis, standardized skin surface biopsy Citation: Friedman P, Cohen Sabban E, Cabo H. Usefulness of dermoscopy in the diagnosis and monitoring treatment of demodicidosis. Dermatol Pract Concept. 2017;7(1):6. DOI: https://doi.org/10.5826/dpc.0701a06 Received: August 13, 2016; Accepted: October 17, 2016; Published: January 31, 2017 Copyright: ©2017 Friedman et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: The authors have no conflicts of interest to disclose. All authors have contributed significantly to this publication. Corresponding author: Paula Friedman, MD, 2562 Arcos St, 2nd floor, Buenos Aires, Argentina. Tel. +0541158406476. Email: paufriedman@gmail.com Demodicidosis is a common infestation and should be considered in the differential diagnosis of recur- rent or recalcitrant perioral dermatitis or rosacea-like eruptions of the face. We report on a 34-year-old male, who presented with facial erythema and desquamation accompanied by a pruritic sensation. Dermoscopic examination revealed Demodex tails and Demodex follicular openings, both specific features of this entity. Microscopically, standardized skin surface biopsy test was pathogenic and the patient had positive response to anti-demodectic drugs. To our knowledge, a few reports of the dermatoscopic features of demodicidosis have been published in the literature. Dermoscopy offers a potential new option for a real-time validation of Demodex infestation and a useful tool for monitoring treatment. ABSTRACT 36 Observation | Dermatol Pract Concept 2017;7(1):6 follicles become heavily infested, or when the mites penetrate the dermal tissue [1,2]. Clinical manifestations include a group of eruptions known ectoparasitic mite, involving mainly the face and head. Although it is controversial, this mite is thought to play a pathogenic role in humans. Symptoms may develop when the Figure 6. Standardized skin surface biopsy. Microscopic visualiza- tion of Demodex folliculorum (original magnification 40x). [Copy- right: ©2017 Friedman et al.] Figure 1. Facial spinulosis (roughness) over an erythematous back- ground. [Copyright: ©2017 Friedman et al.] Figure 2. Facial erythema and desquamation on both cheeks and frontotemporal area. [Copyright: ©2017 Friedman et al.] Figure 3.  Dermoscopic picture: Demodex ‘‘tails” (arrow), Demo- dex ‘‘follicular openings” (star), filaments protruding out of follicu- lar openings (circle), erythema and non-specific scales. [Copyright: ©2017 Friedman et al.] Figure 4.  Dermoscopic picture: Demodex ‘‘tails” (arrow), Demo- dex ‘‘follicular openings” (star) and non-specific scales. [Copyright: ©2017 Friedman et al.] Figure 5. Dermoscopic picture: Demodex ‘‘tails” (arrow), Demodex ‘‘follicular openings” (star). [Copyright: ©2017 Friedman et al.] Observation | Dermatol Pract Concept 2017;7(1):6 37 applying topical corticosteroids for a long period, so we concluded this was a case of secondary DD due to topical steroid therapy [3]. The most important differential diagnoses are papulopustular or ery- thematotelangiectatic rosacea and seb- orrheic dermatitis (Table 2). Folliculitis, perioral dermatitis, contact dermatitis and acne can also be included [4,5]. Our case is an example of how dermos- characterized by variable degrees of spinulosis (roughness of the skin), ery- thema, papules, and pustules, usually accompanied by a burning or pruritic sensation. Primary DD is characterized by the absence of preexisting or con- current inflammatory dermatoses. An abnormal increase of Demodex mites in patients with other known dermatoses or diseases can be classified as second- ary DD (Table 1). Our patient had been copy could have helped in demodici- dosis recognition, since the patient was incorrectly treated with topical steroids possibly with the diagnosis of seborrheic dermatitis. However, when we evaluated the patient, dermoscopy did not reveal what would be expected for seborrheic dermatitis (dotted vessels in a patchy distribution and fine yellowish scales), but revealed, instead, features associated with demodicidosis (‘‘Demodex tails’’ and ‘‘Demodex follicular openings’’). The diagnosis of DD should be made based on three major criteria: the specific clinical presentation, the micro- scopic observation of a high density of mites and a positive response to anti- demodectic drugs [6]. Under dermoscopy, we observed non-follicular and perifollicular gelati- nous threads or filaments protruding out of follicular openings known as “Demo- dex tails.” They account for the presence of the mite itself. Demodex follicular openings were also identified as dilated follicular openings containing round, amorphic, grayish/light brown plugs sur- rounded by an erythematous halo. They are both specific features of DD. The density of Demodex mites can be studied by SSSB, potassium hydroxide examination, skin biopsy, or a combina- tion of these. SSSB is considered to be the gold standard for diagnosis; with this method, the superficial parts of the horny follicle layer are collected and live mites can be observed on microscopic exami- nation. A density of more than 5 mites/ follicles or 5 mites/cm2 of SSSB specimen is considered to be pathogenic [7]. Various therapeutic regimens have been proposed to treat DD, including acaricides— ivermectin, permethrin, crotamiton, lindano—and adjuvants, such as systemic and topical metroni- dazole, salicylic acid, gamma benzene hexachloride, sublimed sulfur and ben- zyl benzoate. Both effectiveness and optimal dosage still remain to be deter- mined. Our patient was treated with ivermectin 1% cream at night for two weeks, and both physical and dermo- scopic examination improved. Figure 8. Dermoscopic pictures before (a) (b) (c) and after treatment (d). [Copyright: ©2017 Friedman et al.] A B C D Figure 7. (a) (c) Secondary demodicosis induced by topical corticosteroid treatment. (b) (d) Rash resolved after two weeks of ivermectin 1% cream at night and a gradual tapering of topical steroid therapy. [Copyright: ©2017 Friedman et al.] A B C D 38 Observation | Dermatol Pract Concept 2017;7(1):6 3. Chen W, Plewig G. Human demodicosis: revisit and a proposed classification. Br J Dermatol. 2014;170(6):1219-1225. 4. Kaur T, Jindal N, Bansal R. Facial demodicidosis: a diagnostic challenge. Indian J Dermatol. 2012;57(1):72-73. 5. Errichetti E, Stinco G. Dermoscopy in general dermatology: a practical overview. Dermatol Ther (Heidelb). 2016;6:471. 6. Segal R, Mimouni D, Feuerman H. Dermoscopy as a diagnostic tool in demodicidosis. Int J Dermatol. 2010;49(9):1018-1023. 7. Aşkın Ü, Seckin D. Comparison of the two techniques for measure- ment of the density of Demodex folliculorum: standardized skin surface biopsy and direct microscopic examination. Br J Dermatol. 2010;162(5):1124-1126. Conclusion Dermoscopy may serve as a useful and non-invasive tool for the real-time identification of Demodex infestation, evalua- tion and follow-up. References 1. Donnelly A, Kenney A, DiCaudo D. Demodicosis: clinical, der- matoscopic, and microscopic correlation. [Abstract]. J Am Acad Dermatol. 2013;68(4):Suppl 1,AB117. 2. Hsu CK, Hsu MM, Lee JY. Demodicosis: a clinicopathological study. J Am Acad Dermatol. 2009;60:453-462. TABLE 1. Secondary Demodicosis Associations. [Copyright: ©2017 Friedman et al.] Acne Perioral dermatitis Papulopustular rosacea Seborrheic dermatitis Calcineurin inhibitors Topical corticosteroids Epidermal growth factor receptor inhibitors Phototherapy Melanocytic nevi Eyelid basal cell carcinoma Mycosis fungoides Systemic diseases (chronic renal failure) Leukemia HIV infection TABLE 2. Differential Diagnosis for Demodicosis—Dermoscopic Clues. [Copyright: ©2017 Friedman et al.] Demodicidosis Seborrheic Dermatitis Rosacea ‘‘Demodex tails’’ ‘‘Demodex follicular openings’’ Dotted vessels in a patchy distribution Fine yellowish scales Erythematotelangiectatic rosacea Linear vessels characteristically arranged in a polygonal network Papulopustular rosacea Linear vessels characteristically arranged in a polygonal network Follicular pustules