Facial sporotrichosis: case series, literature review and new insights about their clinical classification

Background Cutaneous sporotrichosis is primarily categorized into lymphocutaneous (LC) and fixed (F) types. Sporotrichosis affecting the extremities typically manifests as a linear lymphangitic pattern, whereas facial sporotrichosis often exhibits atypical clinical features, thereby making it difficult to be classified. Objective This study aims to analyze the distribution patterns of facial sporotrichosis and proposes novel insights into the clinical classification of atypical facial sporotrichosis based on facial lymphatic drainage patterns. Methods This study presents a case series of seven cases with facial sporotrichosis and systematically reviews the relevant literature. All cases were evaluated for lesion distribution patterns (multifocal vs. localized) and linear arrangement (yes vs. no) according to our predefined criteria for classification. Results Among our seven cases, six presented with multifocal distributions while one exhibited localized distributions. A systematic literature search identified 53 articles encompassing 84 facial sporotrichosis cases. Multifocal lesions predominated, occurring in 64 cases (76.2%). Among the 64 cases of facial sporotrichosis with multifocal lesions, 47 exhibited a non-linear pattern of lesion arrangement. This distribution comprised 26 of the 30 F-type cases, 7 of the 19 LC-type cases, and 14 of the 15 cases that were not definitively classified. Conclusion Currently, the clinical classification of facial sporotrichosis presenting with multifocal and non-linear lesions remains unclear. Based on an analysis of the distribution patterns of these lesions and incorporating evaluation of facial lymphatic drainage characteristics, we propose that such multifocal, non-linear manifestations could be considered the LC type.