A 53-year-old intensive care nurse receiving monotherapy with efalizumab for psoriasis involving her arms, legs, and nails presented with a several-week history of slowly progressive green discoloration of both thumbnails, which were affected by psoriasis-induced onycholysis.
Which one of the following conditions is the most likely to be responsible for this clinical picture?
- Excessive fluoride supplementation
- Hyperbilirubinemia
- Treatment with tetracycline
- Trichophyton rubrum infection
- Pseudomonas aeruginosa infection