Achenbach's Syndrome: The Case of a Benign Paroxysmal Blue Finger.

Achenbach's syndrome, or paroxysmal finger haematoma, is a rare but benign vascular phenomenon characterized by the sudden onset of pain, swelling, and dramatic blue-purple discoloration of a finger, typically without trauma or systemic illness. Although benign and self-limiting, it is frequently under-recognized and often triggers emergency referrals due to its dramatic clinical appearance. We present a case of a 45-year-old man who developed acute volar finger ecchymosis while demonstrating cardio-pulmonary resuscitation compressions, with no underlying pathology identified. A detailed literature review highlights the condition's typical presentation, diagnostic challenges, and potential for misdiagnosis as more serious vascular events, such as digital ischaemia or vasculitis. Our case emphasizes the critical role of clinical recognition in avoiding unnecessary investigations and treatments. Increased awareness of Achenbach's syndrome among clinicians is essential to ensure accurate diagnosis, patient reassurance, and optimal use of healthcare resources.