It is also caused by trauma. In most cases, when white spots appear on a single or a couple of fingers or toes, the most common cause is injury to the base (matrix) of the nail. When this is the case, white spots disappear after around eight months, which is the amount of time necessary for nails to regrow completely. The pattern and number of spots may change as the nail grows. Longitudinal leukonychia
Longitudinal leukonychia is far less common and features smaller 1mm white longitudinal lines visible under the nail plate and parallel to the nail bed. It may be associated with Dariers disease. Cause
It is harmless and most commonly caused by minor injuries, such as nail biting, which occur while the nail is growing. Leukonychia occurs most commonly in healthy individuals, and is unrelated to any known nutritional or physiological deficiency. When caused by injury the marks will disappear as the nail grows outwards. While there are various sources that link dietary needs or vitamin deficiency with recurrent leukonychia, this notion has been challenged by some medical researchers.Other possible reasons for this problem with nail colour can be linked to:

Arsenic poisoning
Lead poisoning
Pneumonia
Heart disease
Kidney failure
Ill health
Hypoalbuminemia
Vitamin deficiency
Ulcerative colitis
Liver cirrhosis
Psychogenic stresses
Onychophagia
Trauma injury
Occupational trauma
Zinc deficiency
Protein deficiency
Psoriasis
Eczema
Iron deficiency

Diagnosis
A doctor will take a thorough medical history, and may take blood tests as well as examining liver and kidney function. Intracellular (red blood cell) assays are more sensitive than tests for plasma levels. Treatment
Improvements have been reported from treating malnutrition associated with zinc deficiency and other minerals. References


== External links ==
Treatment of overdose
As for bupivacaine, Celepid, a commonly available intravenous lipid emulsion, can be effective in treating severe cardiotoxicity secondary to local anaesthetic overdose in animal experiments and in humans in a process called lipid rescue. References
External links
"Ropivacaine". Drug Information Portal. U.S. National Library of Medicine. "Ropivacaine hydrochloride". Drug Information Portal. U.S. National Library of Medicine.