The painful purple digit: an alarming complication of Candida albicans antigen treatment of recalcitrant warts.

Candida albicans (CA) antigen immunotherapy for recalcitrant warts is a novel treatment that has had much success in the recent past. Although several side effects are well documented in the literature, we report a new adverse reaction to CA antigen immunotherapy for verruca vulgaris of the distal fingertip. Our patient received an intradermal injection of CA antigen solution into periungual warts located on the distal left thumb and distal subungual area of the left index finger. Within 24 hours, the patient reported pain, edema, and a purple hue to only the index finger. Incision of the finger demonstrated no hematoma or compartment syndrome. Although the etiology is unknown, we believe the condition was most likely due to edema and vascular compromise secondary to a vigorous delayed-type hypersensitivity reaction, possibly leading to cyanosis of the distal index finger. We report this case to make physicians who use intralesional CA antigen aware of a new possible complication at this anatomic location.