NIC Nail Technician Written ExamScientific ConceptsHard
A client complains that their toenails are often discolored with a yellowish-green hue, and sometimes the nail plate lifts from the nail bed. This condition is most likely caused by:
- AOnychomycosis
- BPsoriasis of the nails
- CTrauma to the nail
- DPseudomonas aeruginosa bacterial infection
Show answer & explanationAnswer & explanation
Correct answer: D. Pseudomonas aeruginosa bacterial infection
The characteristic yellowish-green discoloration of the nail, often accompanied by onycholysis (nail lifting), is a strong indicator of an infection with Pseudomonas aeruginosa bacteria. This bacterium produces pigments that stain the nail.
Why the other options are wrong
- A. Onychomycosis (fungal infection) typically causes yellow, brown, or white discoloration, and thickening, but not usually a distinct 'yellowish-green' hue.
- B. Psoriasis of the nails can cause pitting, discoloration, and onycholysis, but the discoloration is typically yellowish-brown ('oil drop' sign), not yellow-green.
- C. Trauma can cause onycholysis or bruising, but usually not a specific yellowish-green discoloration unless a secondary infection develops.
Pseudomonas aeruginosa Nail Infection
A bacterial infection of the nail, often characterized by a distinctive greenish-yellow discoloration and onycholysis (nail plate separation).
- Caused by the bacterium Pseudomonas aeruginosa
- Thrives in moist environments (e.g., under artificial nails, wet shoes)
- Produces pyocyanin, a blue-green pigment, which stains the nail
Memory trick: Green nails = 'Pseu-do' (pseudo) a green color.