Dermatology: Practical and Conceptual 292 Letter | Dermatol Pract Concept 2018;8(4):7 DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Introduction We report on a case of a 82-year-old woman referred to us with a 2-month history of comedones and multiple yellow- colored cysts, ranging from 0.5 to 5 mm in diameter, located within erythematous plaques on her right malar region (Fig- ure 1a). The left side was spared (Figure 1b). The patient had a history of smoking. She had been a factory worker indoors for 40 years and she denied significant sun exposure. Case Presentation Dermatoscopy showed yellowish lobular-like structures with rare peripheral telangiectasia (Figure 1c). Actinic keratosis, lentigo solaris and seborrheic keratosis were also detected on her face, mainly on her forehead, nose and periorbital areas. A punch biopsy was performed and histopathology revealed massive dermal elastosis and cystic-like spaces. The cystic-like spaces were lined by a flattened epithelium and were filled with layered horny material. The sebaceous glands were atrophic (Figure 1d). Considering clinical, dermoscopic and histological find- ings was diagnosed unilateral Favre-Racouchot disease (FRD). Discussion FRD is characterized by nodules and cysts associated with the clinical signs of actinic-related skin damage and solar elastosis of the face. In 1888 Thin et al. described grouped comedones occurring in solar-damaged skin of elderly individuals for the first time. In 1951, Favre and Racouchot extended this description to include nodular elastosis and cysts [1]. FRD occurs in up to 6% of patients aged from 40 to 60 years, and most are Caucasian men [1]. Sun exposure, smoking, and therapeutic radiation are considered important risk factors. In this disease, 3 pathogenetic steps are described: 1) loss of functional elastic tissue network and reduction of tensile strength; 2) distension of the infundibular canal of the seba- ceous follicles; and 3) retention of sebum with consequent comedones formation [1]. A case of unilateral inflamed plaques with comedones of the face Marco A. Chessa1, Federica Filippi1, Francesca Ferrara1, Annalisa Patrizi1, Carlotta Baraldi1 1 Dermatology, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Italy Key words: Favre-Racouchot syndrome, comedones, nodules and cysts, solar elastosis, yellowish lobular-like pattern Citation: Chessa MA, Filippi F, Ferrara F, Patrizi A, Baraldi C. A case of unilateral inflamed plaques with comedones of the face. Dermatol Pract Concept. 2018;8(4):292-294. DOI: https://doi.org/10.5826/dpc.0804a07 Received: March 18, 2018; Accepted: March 28, 2018; Published: October 31, 2018 Copyright: ©2018 Chessa 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: Federica Filippi, MD, Dermatology, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Via Massarenti 1, 40138, Bologna, Italy. Email: federicafilippi8@gmail.com Letter | Dermatol Pract Concept 2018;8(4):7 293 The skin areas usually involved are the lateral canthi of the eyes, the malar regions, as in our patient, temples, cheeks or neck and the posterior auricular skin. Usually, this disease has a symmetrical distribution even though some cases of unilateral FRS have been reported in the literature [2]. Clinically, the skin involved is characterized by slowly progressive waxy and soft plaques with open or closed com- edones. The surrounding skin may be thickened and shows deep furrows, isolated papules, nodules and rough and waxy plaques from 2 to 6 cm in diameter. Figure 1. (a) Inflamed plaque with comedones and yellow cysts localized on right malar region; (b) left side of face was spared by Favre- Racouchot disease; (c) yellowish lobular-like structures with rare telangiectasia were detected at dermatoscopy; (d) thinning of the epidermis, massive dermal elastosis and cystic-like spaces. The sebaceous glands are atrophic (H&E 4×). [Copyright: ©2018 Chessa et al.] Figure 2. (a) Inflamed plaque with comedones on the right malar region; the black rectangle indicates the site where the skin biopsy was performed; (b) reduction of inflammation with improvement of the skin appearance after application of fusidic acid and tretinoin 0.05% for 2 months. [Copyright: ©2018 Chessa et al.] 294 Letter | Dermatol Pract Concept 2018;8(4):7 Conclusion Our patient refused both surgical and laser therapy, so a topi- cal treatment was started. Fusidic acid and tretinoin 0.05% creams were applied on the lesion once a day for 2 months, achieving a reduction of inflammation and a clinical improve- ment of the disease (Figure 2 a,b). References 1. Patterson WM, Fox MD, Schwartz RA. Favre-Racouchot disease. Int J Dermatol. 2004;43(3):167-169. 2. Vogel S, Mühlstädt M, Molin S, Ruzicka T, Schneider J, Herzinger T. Unilateral Favre-Racouchot disease: evidence for the etiological role of chronic solar damage. Dermatology. 2013;226(1):32-34. Clinical and histopathological findings usually play a piv- otal role in coming to the diagnosis and ruling out chloracne, sebaceous adenoma, and syringoma [1]. The dermoscopic features of FRD have not been reported in the literature before. Histopathologically, FRD is charac- terized by an alteration of the pilosebaceous unit; dilated infundibulum and large, round cystic like spaces are present. Regression or absence of sebaceous glands is often detected. In addition, solar elastosis could be pronounced, but it may also be slight or absent [1]. Sunscreen and cessation of smoking can arrest the pro- gression of the disease. Besides these measures, pharmacologi- cal and surgical approaches could be effective.