We read with great interest a case report by Chessa et al [ 1 ] , which seems to be the first case describing the distinct clinical and dermoscopic features of Favre-Racouchot disease (FRD). We present another patient with similar features.
A 71-year-old man, retired bricklayer, presented with an asymptomatic, erythematous plaque with agminated whitish waxy and hyperkeratotic papules within the right malar area ( Figure 1A ). The lesion had developed several months before. In addition, disseminated individual comedones, small cysts, solar elastosis, and telangiectasia were present on both cheeks and nose. The patient had a history of basal cell carcinoma, hidradenitis suppurativa, type 2 diabetes, permanent atrial fibrillation, 25 pack-years of cigarette smoking, and chronic professional as well as recreational sun exposure. Dermoscopy showed pinkish white globular structures intersected with the yellowish structureless areas corresponding with the presence of a crust ( Figure 1, B and C ).
Figure 1 .
(A) Clinical presentation: an erythematous plaque with agminated whitish waxy and hyperkeratotic papules within the right malar area. (B,C) Dermoscopic presentation: pinkish white globular structures intersected with the yellowish structureless areas corresponding with the presence of a crust. [Copyright: ©2019 Sobjanek et al.]
In differential diagnosis FRD, pyoderma vegetans, sarcoidosis, tuberculosis, and papillated variant of Bowen disease were considered. Histopathological examination revealed cryptic invagination of the infundibular portion of the hair follicle filled with the horny material with overhanging polypoid protrusion of the skin with comedo-like dilation of the other infundibulum, confirming the diagnosis of FRD ( Figure 2 ).
Figure 2 .
(A) Cryptic invagination of the infundibular portion of the hair follicle filled with the horny material with overhanging polypoid protrusion of the skin with comedo-like dilation of the other infundibulum. (B) One of the follicles shows suppurative inflammation and dense lymphoplasmacellular infiltrate in the stroma. [Copyright: ©2019 Sobjanek et al.]
FRD is a relatively common disorder, and usually the diagnosis can be simply made based on clinical presentation [ 2 ] . The unique morphology and unilateral location in both discussed cases made the diagnosis more difficult. The presence of disseminated comedones and signs of photo-damage could serve as a clue to diagnosis. Dermoscopic presentation in both cases was very similar and to our knowledge not typical of any known dermatosis.
- A case of unilateral inflamed plaques with comedones of the face Chessa MA, Filippi F, Ferrara F, Patrizi A, Baraldi C. Dermatol Pract Concept.2018;8(4):292-294.
- Favre-Racouchot disease: systematic review and possible therapeutic strategies Paganelli A, Mandel VD, Kaleci S, Pellacani G, Rossi E. J Eur Acad Dermatol Venereol.2019;33(1):32-41.