Paclitaxel-Induced Periarticular Thenar Erythema with Onycholysis Syndrome.

Introduction: Periarticular thenar erythema with onycholysis (PATEO) syndrome is a rare subtype of hand-foot syndrome seen in patients undergoing taxane-based chemotherapy. It presents as erythematous to violaceous plaques on the dorsum of hands, feet, and around the Achilles tendon along with nail changes, particularly onycholysis. Case Presentation: A 39-year-old female on paclitaxel chemotherapy for stage IIIA (T3N2aM0) invasive ductal breast carcinoma, presented with mildly tender erythematous to violaceous plaques involving the dorsa of bilateral hands and feet, in the periarticular areas of the Achilles tendon, with facial involvement. All fingernails showed shortening, orange-red chromonychia, Beau's lines, onychoschizia, and subungual debris. The toenail involvement was relatively less severe, with distal onycholysis being the predominant finding. The patient showed significant improvement in cutaneous lesions with topical steroid therapy and was advised cold water immersion during subsequent chemotherapy infusions. Discussion: A shorter interval between cycles and a higher cumulative number of cycles correlate with severity of dermatitis and nail involvement. Rarely, periocular and facial involvement can occur concurrently with PATEO syndrome. This case is being reported to increase awareness about this entity facilitating early diagnosis and treatment.