For those of us who love to know the medical terminology, nail discoloration is termed “chromonychia.” “Chrom” is Greek for “color,” and “onukh” is Greek for “nail.” Alternatively, it can be termed “Nail dyschormia” — “dys-” is Greek for “bad.”
Many things can cause nail discoloration, from genetic to infectious to traumatic. A change in color could be due to conditions of the surface of the nail, the entire nail depth, or the skin under the nails. The possible causes are endless, so here is a list of the most common ones:
Infection
Onychomycosis (fungal nail infection) is the most common cause of nail discoloration. Usually the discoloration is white, but it is sometimes greenish in certain fungal or bacterial infections. In either case, exposure to moisture is a primary risk, and patients are always advised to lessen the exposure of their hands to water (or use rubber gloves) and to always dry hands thoroughly after washing them. If the infection is minor, then it can be treated topically, but sometimes oral treatment may be needed. Treatment will require months, and during that time, nail tools should not be shared with others, or even used on your own non-infected nails.
Trauma
Trauma, like playing too hard or over manicuring, causes those very common transverse white lines that are usually found in the fingernails of children and younger adults. If trauma is severe enough, like dropping something really heavy on your toes and blood is trapped underneath, it’s not the nail itself that has changed color, but the blood underneath that gives your nail a red, purple, blue, or black color.
Staining
Staining is common in smokers. Also, some hair dyes and the overuse of nail polish (with no protective base coat) can lead to staining of the nails.
Disease
Certain skin diseases, such as psoriasis or lichen planus, can cause nail discoloration. Systemic diseases that are associated with chromonychia include liver, heart and lung disease, diabetes, systemic lupus erythematosus, and rheumatoid arthritis.
Malnutrition
Vitamin B12 deficiency can cause black bands on the nails.
Medications
Tetracycline can give nails a yellow color. Minocycline and antimalarials give them a blue color. Chemotherapy can give them a brown/black color.
It could be normal
Don’t be alarmed right away if your nails are discolored. Some people are simply born with a tendency for white bands on their nails. People with skin types V and VI commonly have brown bands on their nails. Hey, even eating an excessive amount of carrots can turn your nails a little yellow!
Bottom Line
There is absolutely no way to include all the possible causes and variations of nail discoloration in one article, as this is something that fills chapters in dermatology books. Nail discoloration can occur in completely healthy individuals, or it can be caused by a disease or infection. It is always worth your while to check with your dermatologist, as they will be able to target possible associated symptoms and can tell you if this is something to worry about or not.
Note: black pigmentation can be indicative of a malignancy if:
- it affects ONE NAIL.
- there is SPREAD around the nail to the skin.
- there is DARKENING or WIDENING of an existing band.
- or if the patient is OVER 50.
Thank you for reading.
Looking for the best skin care? FutureDerm is committed to having its customers find — and create — the best skin care for their individual skin type, concern, and based on your ingredient preferences. Learn more by visiting the FutureDerm shop!
Sources:
P. Rich, RK Scher. Chromonychias. In: An Atlas of Diseases of the Nails. Second Edition. Parthenon Publishing 2005: 47-60.
WD. James, TG. Berger, DM Elston. Diseases of the Skin Appendages. In: Andrew’s Diseases of the Skin: Clinical Dermatology. Tenth Edition. Elsevier Saunders 2006: 789-92.
E. Haneke et al. Nail Color Changes (Chormonycnia). In: R. Baran et al. A Text Atlas of Nail Disorders: Techniques in Investigation and Diagonsis. Third Edition. Martin Duntiz 2003: 175-95.