Disorders or irregularities of the nails are common findings in medical practice and can be benign or pathalogic and indicative of local or systemic conditions.
II. Diagnostic Approach
A. What is the differential diagnosis for this problem?
Conditions involving all nails:
Conditions involving few nails to one nail:
B. Describe a diagnostic approach/method to the patient with this problem
Diagnosis is through history and physical examination as set out in the sections below, with laboratory tests used to reveal underlying systemic disorders.
1. Historical information important in the diagnosis of this problem.
Are the findings confined to one nail or present on most nails? Is the finding an irregularity in nail architecture or a color change? Is the abnormality a new change or a chronic finding? Further questioning should focus on known medical problems, exposures to medications or toxins, and a thorough review of systems for undiagnosed systemic disorders.
2. Physical Examination maneuvers that are likely to be useful in diagnosing the cause of this problem.
Examine all nails of the hands and feet. Make a visual inspection of affected nails for irregularities in shape and color. Note should be made if color changes extend across the nail or with the plane of growth and whether they involve the totality of the nail or only a portion. Concern for clubbing should be further evaluated by a Schamroth’s test (obliteration of the normal diamond-shaped space at the proximal end of the nail when the distal phalanges are opposed). Palpate nails for irregularity of surface. Compress the nail bed to assess for pain and capillary refill. A suspicion for underlying systemic disease should prompt an appropriately targeted examination of other organ systems.
3. Laboratory, radiographic and other tests that are likely to be useful in diagnosing the cause of this problem.
Common laboratory tests that may be revealing for underlying systemic disorders affecting the nails include hemoglobin with mean corpuscular volume for iron deficiency anemia (koilonychia), blood urea nitrogen and creatinine for renal failure (Lindsay’s nails), liver function tests for hepatic disease (clubbing, Terry’s nails) and hypoalbuminemia (Muehrcke’s lines), and chest radiography for pulmonary disease and malignancy (clubbing).
In the absence of a suspicion for systemic disease, specific laboratory or imaging tests are often not necessary. A concern for splinter hemorrhage should lead to further evaluation for endocarditis, usually involving echocardiography. A concern for subungal melanoma should lead to prompt consultation for biopsy of the lesion
C. Criteria for Diagnosing Each Diagnosis in the Method Above.
Beau’s lines are transverse depressions of the nail. They can result from trauma, exposure to cold, chemotherapy, Raynaud’s disease, or any process that disrupts normal nail growth. As nails grow approximately 1mm every ten days, estimation of the time of systemic insult can be obtained by measuring the distance from the palpable transverse depression to the nail bed.
Hypertrophic osteoarthropathy, commonly referred to as “clubbing,” is diagnosed by performing a Schamroth’s test (described in physical examination maneuvers above). Though it’s exact cause is poorly understood, clubbing results from thickening of the soft tissue beneath the proximal nail plate. Conditions commonly associated with clubbing include neoplastic processeses, often of the lung or pleura, bronchiectasis, lung abscess, pulmonary fibrosis, cystic fibrosis, arteriovenous (AV) malformations, cirrhosis, celiac disease, inflammatory bowel disease, hyperthyroidism, congenital heart disease, and endocarditis. Hypertrophic pulmonary osteoarthropathy refers specifically to a combination of clubbing and thickening of the periosteum and synovium that is usually associated with lung cancer.
Koilonychia appears as concavity of the nails, resulting in a “spoon shaped” appearance. The finding is commonly associated with iron disorders including both iron deficiency and hemochromotosis. Koilonychia can also be seen with frequent exposure of the nails to petroleum-based solvents, Raynaud’s disease, systemic lupus erythematosus, trauma, and the nail-patella syndrome (a hereditary autosomal-dominant condition).
Lindsay’s nails, also referred to as “half-and-half” nails, show the proximal portion of the nail as white and the distal half as brown. The disorder is most commonly seen in renal failure, hemodialysis patients, and kidney transplant recipients.
Muehrcke’s lines manifest as transverse white lines that extend beneath the entire nail. The white lines result from edema in the underlying nail bed and should dissapear with compression of the nail. The lines do not move with nail growth. This finding is commonly associated with hypoalbuminemia, specifically when the albumin level falls below 2.2gm/dl, and may be present in patients with nephrotic syndrome, liver disease, and malnutrition.
Nail pitting manifests as punctate depressions in the nail plate. It is often associated with psoriasis, but may be seen with systemic diseases such as psoriatic arthritis, reactive arthritis, sarcoidosis, pemphigus, and alopecia areata.
Terry’s nails appear as opaque nails, with obliteration of the lunula and appearance of a distal brown transverse band. Such findings can be normal in elderly patients, though they are often associated with the pathologic states of cirrhosis, congestive heart failure, diabetes mellitus, hyperthyroidism, and malnutrition.
Leukonychia are nonuniform white lines found in different areas on one or more nails and do not span the entire nail. They are often the result of sporadic trauma to the proximal nail bed and usually of little clinical significance.
Splinter hemorrhages are thin red or brown longitudinal lines beneath the nail. They occurr as a result of disruption of blood vessels running through dermal ridges along the axis of growth beneath the nail plate. Most commonly they are associated with local trauma, although they can also be seen in endocariditis, cirrhosis, vasculitis, trichinosis, psoriasis, and scurvy.
Subungual hematoma is a collection of blood beneath the nail often as a result of trauma. Blood can collect under the nail plate causing elevated sunungual pressures leading to throbbing pain.
Subungal melanoma can appear as a longitudinal pigmented band. Factors that have been identified which increase the likelihood of melanoma in a patient with a longitudinal pigmented nail band include a new longitudinal band in a light-skinned person, sudden change in appearance of a band, single nail involvement, pigmentation of the skin of the nail fold or proximal nail bed, new pigmentation in older persons, band width of more than 3mm, a family history of melanoma or dysplastic nevi, and abnormalites of the nail structure.
D. Over-utilized or “wasted” diagnostic tests associated with the evaluation of this problem.
III. Management while the Diagnostic Process is Proceeding
A. Management of disorders of nails
Most nail findings in and of themselves do not necessitate emergent treatment but can certainly be an external manifestation of a serious underlying systemic illness. Management should focus on recognition of the underlying condition and implementing disease-specific therapy.
Concern for subungual melanoma should initiate prompt consultation for biopsy of the lesion.
A symptomatic subungual hematoma may necessitate a release of pressure from the pooled blood beneath the nail plate. A heated instrument is often used to pass through the nail into the hematoma for evacuation. Alternatively, the nail can be completely removed. Asymptomatic subungual hematomas can be managed expectantly with counseling that the nail will likely fall off on its own.
B. Common Pitfalls and Side-Effects of Management of this Clinical Problem
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- I. Problem/Condition.
- II. Diagnostic Approach
- A. What is the differential diagnosis for this problem?
- B. Describe a diagnostic approach/method to the patient with this problem
- 1. Historical information important in the diagnosis of this problem.
- 2. Physical Examination maneuvers that are likely to be useful in diagnosing the cause of this problem.
- 3. Laboratory, radiographic and other tests that are likely to be useful in diagnosing the cause of this problem.
- C. Criteria for Diagnosing Each Diagnosis in the Method Above.
- D. Over-utilized or “wasted” diagnostic tests associated with the evaluation of this problem.
- III. Management while the Diagnostic Process is Proceeding
- A. Management of disorders of nails
- B. Common Pitfalls and Side-Effects of Management of this Clinical Problem