Question:
A 17 year old girl with acne has been taking a drug for the last two years. She now presents with blue black pigmentation of nails. The likely medication causing the above pigmentation is:
A 17 year old girl with acne has been taking a drug for the last two years. She now presents with blue black pigmentation of nails. The likely medication causing the above pigmentation is:
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Which tetracycline is famous for blue black pigment in skin, nails, and sclera.
Updated On: Jun 24, 2026
- Tetracycline
- Minocycline
- Doxycycline
- Azithromycin
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Verified By Collegedunia
The Correct Option is B
Solution and Explanation
Step 1: The clue is long term acne treatment that has caused blue black pigmentation. Among acne drugs, the tetracycline group is used for months to years.
Step 2: Minocycline is the one tetracycline well known for causing blue black or slate grey pigmentation. It binds to melanin and iron and forms pigment deposits in skin, nails, sclera, oral mucosa, teeth, and old scars.
Step 3: So minocycline best fits blue black nail pigmentation after two years of acne therapy. Option B is correct.
Step 4: Why not the others. Plain tetracycline and doxycycline can cause photosensitivity and tooth staining in young children, but blue black pigmentation of nails is a hallmark of minocycline, not them. Azithromycin is a macrolide used in short courses and does not cause this pigment.
Step 5: Stopping the drug usually leads to slow fading of the pigment.
Answer: Minocycline.
Step 2: Minocycline is the one tetracycline well known for causing blue black or slate grey pigmentation. It binds to melanin and iron and forms pigment deposits in skin, nails, sclera, oral mucosa, teeth, and old scars.
Step 3: So minocycline best fits blue black nail pigmentation after two years of acne therapy. Option B is correct.
Step 4: Why not the others. Plain tetracycline and doxycycline can cause photosensitivity and tooth staining in young children, but blue black pigmentation of nails is a hallmark of minocycline, not them. Azithromycin is a macrolide used in short courses and does not cause this pigment.
Step 5: Stopping the drug usually leads to slow fading of the pigment.
Answer: Minocycline.
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