Adult-Onset Phalangeal Microgeodic Syndrome: A Case Report and Literature Review.

Phalangeal microgeodic syndrome (PMS) is a rare condition thought to result from a transient disturbance of peripheral circulation under cold temperatures. PMS is most prevalent in children, mainly affecting the fingers and rarely the toes. Although some cases of adult-onset PMS have been reported, the clinical features remain unclear. Herein, I report the case of a 24-year-old man who developed PMS with toe involvement. The self-limiting course was followed by magnetic resonance imaging (MRI). Furthermore, I performed a literature review and summarized the characteristics of this case and eight previously reported adult-onset PMS cases (n=9). The median patient age was approximately 43 (range: 18-89) years, and most cases were diagnosed based on frostbite-like symptoms in winter and specific MRI findings, despite normal radiographic findings. While adult-onset cases had similar clinical and imaging features to child-onset cases, toe involvement was frequent (5/9 [56%]), and female patients were dominant (8/9 [89%]). Two patients had immune-mediated diseases, such as systemic lupus erythematosus and psoriasis. These reports suggest that adults and children with PMS have some different clinical characteristics. Thus, clinicians should consider PMS when finger or toe pain occurs in cold environments, even in adults.