When is topical antibiotic therapy recommended for green nail syndrome?

Green nail syndrome, also called a pseudomonas nail infection, can cause green discolouration beneath or around a nail, often where moisture has collected or the nail has lifted. The colour alone does not establish the diagnosis: trauma, fungal disease, staining, and other nail problems can look similar.

A clinician may select a topical antibiotic when the infection appears limited and the nail can be treated locally. The plan may also involve keeping the nail dry, trimming only loose nail safely, and addressing a gap between the nail and nail bed. A medicine should not be applied under a firmly attached nail unless specifically directed.

Follow the prescribed frequency and duration, and wash and dry the area before application if advised. Keep hands or feet dry, wear breathable footwear, and avoid nail polish, artificial nails, and picking until the nail has been assessed. Do not share nail tools, towels, or medication.

Nails grow slowly, so colour may not disappear immediately even when the infection is improving. Attend the planned review if the discolouration spreads, the nail becomes more detached, or the treatment causes burning, swelling, or a rash.

Seek prompt care for increasing pain, warmth, swelling, pus, or redness extending onto the finger or toe. Fever, red streaks, or rapid change after an injury warrants urgent assessment. A dark mark that does not fit the usual pattern of green discolouration also needs examination.

Ask how the diagnosis was made, whether the nail should be trimmed, how to keep it dry, and when a review is needed. Ask which changes suggest fungal disease, a deeper infection, or a different nail condition.