Nails are often thought to be "lifeless" structures, but nothing could be further from the truth. Nails are extensions of the skin, and so nail discoloration can provide clues to the presence of not only nail diseases, but various other medical conditions.
Discolored Nails in Yellow Nail Syndrome
In yellow nail syndrome, the nails become thick and yellow to yellowish-green in colour. Their rate of growth may slow and in severe cases they can become separated from the nail bed. Yellow nail syndrome is often associated with lymphoedema (swellings due to a blockage in the lymphatic system), pleural effusions (accumulation of fluid between the lung and the chest wall) or, less commonly, chronic chest infections or sinusitis.
Yellow nail syndrome is rare and its cause is unknown. Any associated chest problems are treated in the appropriate way, while the nails may benefit from vitamin E therapy in the form of a solution that is rubbed into the affected areas or a dietary supplement.
Fungal nail infection, psoriasis, smoking and nail polish can also cause yellowing of the nails.
Splinter Haemorrhages Under the Nails
Splinter haemorrhages are small areas of bleeding beneath the nails. They appear as narrow red or reddish-brown lines running along the nail’s length. The most common cause is an injury to the nail, though they can occur in people who have an infection of the heart valves (endocarditis). When caused by injury, splinter haemorrhages disappear gradually as the nail grows out.
Dark Streaks in the Nail
A brown or black streak running lengthwise along the nail can have various causes, some minor and others serious.
- A subungual haematoma is a larger collection of blood beneath the nail, caused by a direct blow or crushing injury. It can be very painful, but usually responds to an ice pack, elevation of the affected hand and anti-inflammatory medications such as ibuprofen. In severe cases, the haematoma may have to be drained by a doctor.
- A naevus (birthmark) can appear as a dark line in the nail.
- Certain drugs, including the antibiotic minocycline, can cause streaking of the nails as a side-effect.
- Nail discoloration is common in people with Addison’s disease, a rare disorder of the adrenal gland.
- Lichen planus and fungal or bacterial infections can produce streaks on the nails.
- A pigmented line in a nail can be a sign of a malignant melanoma or other skin cancer.
Other Nail Colour Changes
Other medical causes of discolored nails include the following conditions.
- White nail beds may indicate problems with the liver or kidneys.
- Brown nail beds occur in chronic kidney disease.
- Blue nail beds are seen as a side-effect of treatment with the drug mepacrine.
- Blue discoloration of the lunula (the whitish area at the base of the nail) is a sign of Wilson’s disease, a genetic disorder in which copper accumulates in the body.
- Red lunulae may indicate heart failure.
Is Nail Discoloration a Cause for Concern?
Most changes in the appearance of the nails are harmless; they may even be self-inflicted, by careless manicure or other nail treatments. There is no need to panic when a colour change occurs – as American College of Physicians spokeswoman Christine Laine explains: “Nail changes are rarely the first clue of serious illness. In most instances, patients will manifest other signs or symptoms of disease before nail changes become evident.” However, people who do have any concerns should never hesitate to consult their doctor for advice.
References:
Disabled World. Fingernails Nail Color Health Indicators. Accessed 03-06-09
Luyten C et al. Yellow Nail Syndrome and Onychomycosis. Experience with Itraconazole Pulse Therapy Combined with Vitamin E. Dermatology 1996; 192(4): 406–8.
MedicineNet. What Your Nails Say About Your Health. Accessed 03-06-09
Williams HC et al. Successful Use of Topical Vitamin E Solution in the Treatment of Nail Changes in Yellow Nail Syndrome. Arch Dermatol 1991; 127(7): 1023–8.
Disclaimer
The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
