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Susan Ivy
Susan Ivy, Nurse (RN)
Category: Health
Satisfied Customers: 4058
Experience:  BSN, MSN, CNS
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The skin under most of my fingernails slowly turned blueish/black

Customer Question

The skin under most of my fingernails slowly turned blueish/black about 3-4 months ago. Being 30 lbs. overweight, I went on a serious count-calories diet eating fruits,vegs. and small amount of meat, no sugar, no white flour, no fats, only grains. Gradually losing weight, feeling great. Now, suddenly the normal nail color is returning. However, several of my nails on my left hand (all except thumb) are normal color with a white horizontal streak across. I have rheumatoid arthritis taking Leflunomide 20 mg. and 7mg. Prednisone daily and no other problems. I'm 62 y.o. female, Portuguese decent. What might this mean.
Submitted: 6 years ago.
Category: Health
Expert:  Susan Ivy replied 6 years ago.

Hello and thank you for using JustAnswer Health for your question.


Horizontal lines across the nail bed (left to right) are called Beau's lines. These lines can occur after illness, injury to the nail, and when you are malnourished.


So there are several different situations that might have caused these nail changes in your case.


You specifically report a change in your nutritional status. Particularly if you fasted at any time, this may be the cause of your Beau lines.


Additionally, I noticed when I read your post, that you stoped eating as much meat. That is fine, and is good in those cases where an individual consumed too much fatty meat. But if your protein intake is significanly low, meaning you are not getting high enough protein intake via other sources this may be what is reflected in the nails as horizontal lines.


Other causes include vitamin deficiencies, surgery, and arsenic poisoning. Basically any thing that is stressful to the body disrupting the normal even process of growth.


I reviewed your medications, and Leflunomide has a potential side effect of suppressing bone marrow and the immune system (your doctor typically watches you for this closely by monitoring your laboratory values). If your bone marrow was suppresse, perhaps when you started this medication, a dose was changed, etc., then it might be responsible for the Beau's lines.


As long as your nail growth has returned to normal, this is not something to worry about. One can tell much about the health of an individual by observing the nails beds, so if you see lines forming again be sure and mention it to your doctor, even though your doctor most likely would catch immune or bone suppression first by monitoring your lab work.


If you have questions or need clarification about anything please feel free to respond back to this post so that I may continue to assist you.



Expert:  Susan Ivy replied 6 years ago.
This is odd, this is now unlocked. I have sent you an answer on the other post as well.