Joe is an eskimo who presents with black fingernails on a background of trauma to his hands after recent red wine consumption.

What are the causes of black discolouration of the nail plate?

• Haematoma
• Melanoma
• Racial pigmentation
• Naevus
• Minocycline
• Cytotoxic drugs

What us the most likely cause in this situation?

1. Trauma

This question is likely to arise in the exams as a picture with the expectation that you can differentiate from melanoma and not miss that. There are specific signs to look for with melanoma discussed on DermNet and in here. https://www.dermnetnz.org/topics/melanoma-of-nail-unit-images/

Reading

1. Murtaghs General Practice Chapter 129 – http://murtagh.mhmedical.com/content.aspx?bookid=1522&sectionid=116046129
2. Murtaghs Practice Tips – Chapter 8 – Nail Problems – http://murtagh.mhmedical.com/content.aspx?bookid=1920&sectionid=143276631
3. https://www.dermnetnz.org/topics/melanoma-of-nail-unit-images/

Podcast

1. GP Core Content Podcast Episode 150 – Dermatology | Nails