Website maintenance is scheduled for Saturday, October 12, and Sunday, October 13. Short disruptions may occur during these days.

brand logo

Am Fam Physician. 2023;107(3):305-306

Author disclosure: No relevant financial relationships.

A 52-year-old woman presented with black discoloration of the fingernails (Figure 1). She had no trauma to the area and no associated pain, rash, swelling, or drainage. She had no other symptoms, including shortness of breath, chest pain, or visual disturbances. Her medical history was significant for type 2 diabetes mellitus, hypertension, thrombocytosis, and coronary artery bypass. The patient was taking metformin, glipizide, lisinopril, hydroxyurea, and topiramate.

Her vital signs were normal on physical examination. All fingernails showed black discoloration but no pitting, spooning, or ulceration. The fingertips were warm to the touch and nontender to palpation.

Question

Based on the patient’s history and physical examination findings, which one of the following is the most likely diagnosis?

 

  • A. Mees lines.

  • B. Melanonychia.

  • C. Onychomycosis.

  • D. Subungual hematoma.

  • E. Subungual melanoma.

 

Discussion

The answer is B: melanonychia. Several medications are known to induce black discoloration of fingernails, including antimalarials, chemotherapeutics (hydroxyurea, cyclophosphamide, fluorouracil), phenytoin, and tetracyclines.1 The discoloration may present as a longitudinal, transverse, or diffuse band pattern. Patients may have coexisting diffuse pigmentation of the skin (melanoderma). Melanonychia can also occur with nutritional deficiencies (folate, vitamin B12), connective tissue diseases (systemic lupus erythematosus, scleroderma), endocrinopathies (Addison disease, Cushing syndrome, hyperthyroidism), or physiologic processes (pregnancy).1

Already a member/subscriber?  Log In

Subscribe

From $165
  • Immediate, unlimited access to all AFP content
  • More than 130 CME credits/year
  • AAFP app access
  • Print delivery available
Subscribe

Issue Access

$59.95
  • Immediate, unlimited access to this issue's content
  • CME credits
  • AAFP app access
  • Print delivery available
Purchase Access:  Learn More

The editors of AFP welcome submissions for Photo Quiz. Guidelines for preparing and submitting a Photo Quiz manuscript can be found in the Authors' Guide at https://www.aafp.org/afp/photoquizinfo. To be considered for publication, submissions must meet these guidelines. Email submissions to afpphoto@aafp.org.

This series is coordinated by John E. Delzell Jr., MD, MSPH, associate medical editor.

A collection of Photo Quiz published in AFP is available at https://www.aafp.org/afp/photoquiz

Continue Reading

More in AFP

More in PubMed

Copyright © 2023 by the American Academy of Family Physicians.

This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP.  See permissions for copyright questions and/or permission requests.