Onychopathy induced by temsirolimus, a mammalian target of rapamycin inhibitor

Area of Science:

• Oncology
• Dermatology
• Pharmacology

Background:

• Mammalian target of rapamycin (mTOR) inhibitors are increasingly used in oncology.
• Mucocutaneous toxicities, including nail disorders, are common side effects of mTOR inhibitors but are not well-characterized.
• Temsirolimus is an mTOR inhibitor used in cancer treatment.

Observation:

• Two patients developed significant nail dystrophy after 6-7 months of temsirolimus treatment.
• Nail changes included fragility, distal onycholysis, and yellow discoloration affecting all 20 nails.
• One patient also experienced painful paronychia, which improved with topical steroids but not the underlying nail dystrophy.

Findings:

• This is the first report of yellow nail discoloration associated with temsirolimus therapy.
• The nail dystrophy presented as a comprehensive 20-nail dystrophy with characteristic features.
• Topical steroids were effective for paronychia but not for the nail dystrophy itself.

Implications:

• This case series highlights a previously unreported side effect of temsirolimus, emphasizing the need for vigilant monitoring of nail health in patients undergoing mTOR inhibitor therapy.
• Understanding and characterizing these nail toxicities can lead to improved patient management and supportive care strategies.
• Further research is warranted to elucidate the mechanisms behind temsirolimus-induced nail changes and to develop targeted interventions.