​​Longitudinal Erythronychia Secondary to a Wooden Splinter

Longitudinal erythronychia (LE) is a term for red streaks in the nail which can be caused by a range of diseases. The specific type of longitudinal erythronychia can correlate with certain associated conditions making it important to properly categorize when discovered. A 71-year-old Hispanic male presented to the clinic with a type 1A LE associated with subungual keratosis that had been asymptomatic for approximately 12 months. The patient denied injury, pain, cold sensitivity, or cosmetic distress. The working diagnosis was squamous cell carcinoma in situ (SCCIS) vs. onychopapilloma or glomus tumor. A 4mm punch biopsy from the distal nail matrix was performed, and dermatopathology revealed that the LE was secondary to a wooden splinter. After a literature review, it was discovered that this is the first confirmed case of LE secondary to a splinter. Future providers should keep splinters as a potential differential diagnosis, especially as they evaluate LE, but ultimately all suspicious type IA lesions should be biopsied to rule out potential insidious pathologies, such as SCCIS and malignant melanoma.