Examining the Fingernails When Evaluating Presenting Symptoms in Elderly Patients
Introduction
Human
fingernails, located on the dorsal aspect of the terminal 40% of the
distal phalanx of each finger, are complex structures involving 3
different layers:
The nail plate (the nail). This is the keratinized structure, which grows throughout life;
The
nail bed (ventral matrix, sterile matrix). This is the vascular bed
that is responsible for nail growth and support. It lies protected
between the lunula (the "half moon" seen through the nail) and the
hyponychium (the posterior part of the nail bed epithelium); and
The eponychium (cuticle). The epidermal layer between the proximal nail fold and the dorsal aspect of the nail plate.
The
primary purpose of the nail is protection. Abnormalities of the nail
are often caused by skin disease and infection (most often fungal) but
may also indicate more general medical conditions. This discussion does
not address localized trauma or nail infections but offers examples of
nail abnormalities that may occur with systemic disease.
Check to see whether the nails are normal by looking at the following (Figure 1):
Softness and flexibility of free edge;
Shape and color;
Quality of paronychial tissue; and
Growth rate (about 6 months from cuticle to free edge). Time of events can be estimated from location.
Figure 1. The normal nail.
Examining the Nails
Elderly
people carry the last 6 months of their medical record on the
approximately 10 square centimeters of keratin comprising the
fingernails. Examining the fingernails can help the clinician detect a
number of general and specific factors, including the following:
Overall vitality;
Inner emotional state;
Cerebral dominance;
Occupations and hobbies;
Medical history;
Nutritional status;
Cardiovascular function;
Rheumatic conditions; and
Dermatologic problems.
The
patient's manicure can reveal state of health, nutritional status, past
events, personality, occupation, and one's inner state. Systemic
illness should show the nail changes in each of the nails on one hand.
The thumb may reveal more extensive changes given its increased size.
It is useful to follow the following sequence when examining the nails:
Check the nail shape;
Examine the nail color;
Survey processes around the nails;
Compare hands; and
Note skin conditions.
It
is critical to examine the nails in adequate light. Gently rotate the
nail in the light so that the reflection highlights all aspects of the
nail. Notice the lunula, the pale crescent moonlike coloration at the
base of the nail. Leukonychia stria and a pointed tent-like lunula
suggest an excessive manicure and pushing on the cuticle. Paronychias
suggest stress and poor attention to hygiene. This can reflect
depression, dementia, or psychiatric illness.
Nail Growth
Nail
growth is continuous. It takes about 6 months for a fingernail in an
elderly person to completely grow out. Cold temperature can slow growth
rates but not to any clinically significant degree (pun intended). The
middle finger nail grows the fastest, followed by the forefinger and
ring finger. Aging slows the growth rate from approximately 3 months in
childhood to 6 months in 70-year-olds. Nails in elderly people are also
thicker than in younger people. Thin nails in a postmenopausal woman
raise the possibility of metabolic bone disease. The nails of the
dominant hand grow slightly more quickly than the nondominant nails,
probably because minor trauma accelerates nail growth. Conversely,
immobility slows the growth rate of fingernails. Understanding the
growth rate is important because the time interval from a critical
event can be estimated from the location of a nail lesion. For example,
a white line appearing transversely halfway up the nail suggests an
acute illness 3 months earlier. Regular observation will demonstrate
its progression to the end of the nail edge.
Nail Polish
Distance
from base and line of polish gives approximate date of application
(nails grow 0.1 mm/day). Picking at polish reflects nervousness and
agitation. Toenail polish suggests unusual flexibility or a friendly
helper.
Observing the Nail Shape and Surface
Clubbed Fingernails
Clubbing
involves a softening of the nail bed with the loss of normal Lovibond
angle between the nail bed and the fold, an increase in the nail fold
convexity, and a thickening of the end of the finger so it resembles a
drumstick.
To
determine whether nails are clubbed, have the patient place both
forefinger nails together and look between them. If you can see a small
diamond space between them (Schamroth's window) then the nails are not clubbed (Schamroth's sign) (Figure 2).
Figure 2. Schamroth's sign.
Causes of clubbing (not exhaustive) include the following (Figure 3):
Pulmonary and cardiovascular causes (80%)
Lung
cancer, pulmonic abscess, interstitial pulmonary fibrosis, sarcoidosis,
beryllium poisoning, pulmonary arteriovenous fistula, subacute
bacterial endocarditis, infected arterial grafts, aortic aneurysm
Gastrointestinal causes (about 5%)
Inflammatory bowel disease, sprue, neoplasms (esophagus, liver, bowel)
Hyperthyroidism (about 1%)
Note: Chronic obstructive pulmonary disease does not cause clubbing.
Figure 3. Example of clubbed fingernails.
Koilonychia
Koilonychia are spoon-shaped concave nails
(Figures 4A, 4B). This occurs normally in children and usually resolves
with aging. To determine whether a nail is spooned, perform the water
drop test. Place a drop of water on the nail. If the drop does not
slide off, then the nail is flattened from early spooning. An
experienced clinician can look at the nail and perform a "mental" water
drop test. Causes include the following:
Iron deficiency;
Diabetes mellitus;
Protein deficiency, especially in sulfur-containing amino acids (cysteine or methionine);
Exposure to petroleum-based solvSystemic lupu
Raynaud's disease.
Figure 4A. Spooned nail.
Figure 4B. Spooned nail.
In 1846, Joseph Honoré Simon Beau described
transverse lines in the substance of the nail as signs of previous
acute illness.. The lines look as if a little furrow had been plowed
across the nail. Illnesses producing Beau's lines include the
following:
Severe infection;
Myocardial infarction;
Hypotension, shock;
Hypocalcemia; and
Surgery.
Intermittent doses of immunosuppressive therapy
or chemotherapy can also produce Beau's lines. Severe zinc deficiency
has also been proposed as a cause of Beau's lines. By
noting its location on the nail, the approximate date of the illness
associated with it can be determined (Figures 5A, 5B). Moreover, the
depth of the line provides a clue to the severity of the illness.
Figure 5A. The location of Beau's lines half way up the nail suggests illness 3 months ago.
Figure 5B. Two Beau's lines suggest illnesses about 2 months apart.
Thin Brittle Nails
Thin, brittle nails can indicate the following (Figure 6):
Metabolic bone disease (nail thinness is correlated with osteopenia);
Thyroid disorder;
Systemic amyloidosis (indicated by yellow waxy flaking); and
Severe malnutrition.
Figure 6. Note the thin nails in this woman with severe osteopenia.
Onychorrhexis is the presence of longitudinal
striations or ridges (Figure 7). It can simply be a sign of advanced
age but it can also occur with the following:
Rheumatoid arthritis;
Peripheral vascular disease;
Lichen planus; and
Darier's disease (striations are red/white).
Central ridges can be caused by:
Iron deficiency;
Folic acid deficiency; and
Protein deficiency.
Figure 7. Example of a central nail ridge.
Central Nail Canal (Median Nail Dystrophy)
When a central nail canal is present, the cuticle is usually normal (Figure 8A). Central nail canal is associated with:
Severe arterial disease ("Heller's fir tree
deformity" -- a central canal with a fir tree appearance -- may occur
with peripheral artery disease (Figure 8B);
Severe malnutrition; and
Repetitive trauma.
Figure 8A. Example of central nail canal.
Figure 8B. Central nail canal with Heller's fir tree deformity.
Nail Pitting
Nail pitting -- small punctate depressions -- are caused by nail matrix inflammation, which can be the result of:
Psoriasis (random appearance of pits) (Figure 9);
Alopecia areata (geometric rippled grid) (Figure 10);
Eczema; and
Lichen planus.
Figure 9. Indication of psoriasis.
Figure 10. Indication of alopecia areata.
Nail Beading
With nail beading, the beads seem to drip down
the nail like wax (Figure 11). It is associated with endocrine
conditions, including the following:
Diabetes mellitus;
Thyroid disorders;
Addison's disease; and
Vitamin B deficiency.
Figure 11. Nail beading.
Rough Nail Surface
When nails look sandpapered and dull, consider (Figure 12):
Autoimmune disease;
Psoriasis;
Chemical exposure; and
Lichen planus.
Figure 12. Example of a rough nail surface.
Nail Thickening
Slow nail growth produces thickness (Figure 13). In such cases, the following should be considered:
Onychomycosis;
Chronic eczema;
Peripheral vascular disease;
Yellow nail syndrome; and
Psoriasis.
Figure 13. Example of a nail thickening.
Onycholysis
Onycholysis is distal separation of the nail
plate from the underlying nail bed (Figure 14). It is associated with
the following:
Thyrotoxicosis;
Psoriasis;
Trauma;
Contact dermatitis;
Tetracycline;
Eczema;
Toxic exposures (solvents);
Blistering from autoimmune disease; and
Porphyria cutanea tarda (onycholysis and skin blistering from sun exposure).
Figure 14. Traumatic onycholysis (involving only 1 nail).
Severe Nail Curvature (Beaked Nails)
Curved or beaked nails are caused by resorption of distal digit (Figure 15). Consider the following:
Hyperparathyroidism
Renal failure
Psoriasis
Systemic sclerosis
Figure 15. Example of severe nail curvature.
Complete Nail Destruction
Complete local nail destruction can be caused
by local mechanisms, including trauma and paronychia. Generalized
conditions that might cause complete nail destruction include the
following:
Toxic epidermal necrolysis;
Chemotherapy;
Bullous diseases; and
Vasculitis.
Observing Nail Color Abnormalities of the Lunula
If the lunula is absent, consider anemia or
malnutrition (Figure 16). A pyramidal lunula might indicate excessive
manicure or trauma (Figure 17). A pale blue lunula suggests diabetes
mellitus. If the lunula has red discoloration, consider the following
causes among others (Figure 18):
Cardiovascular disease;
Collagen vascular disease; and
Hematologic malignancy.
Figure 16. Absent lunula.
Figure 17. Pyramidal lunula.
Figure 18. Lunula with red discoloration.
Transverse White Lines (Mee's lines)
Any acute illness can produce transverse milky
white lines. In addition, they might be caused by heavy metal toxicity
(classically arsenic) or chemotherapy. The time of event may be
determined from the location of the lines on nail (Figure 19).
Figure 19. Note the Mee's line approximately one third of the way up the nail, suggesting a significant illness 2 months previously.
Leukonychia Striae
Leukonychia striae are white splotches caused
by minor trauma to the nail matrix (Figure 20). The timing can be
determined by the location of the splotches on the nail.
Figure 20. Example of leukonychia striae. Note location of white splotches, which can indicate timing of the traumatic event.
Longitudinal Brown Lines
Longitudinal brown lines form because of
increased melanin produced by nail matrix melanocytes (Figure 21). They
are associated with:
Addison's disease;
Nevus at the nail base;
Breast cancer;
Melanoma (check for periungal pigmentation); and
Trauma.
Figure 21. Longitudinal brown lines.
Splinter Hemorrhages
Splinter hemorrhages are caused by hemorrhage
of the distal capillary loop (Figure 22). Note the thickness of these
areas. They are associated with the following:
Subacute bacterial endocarditis;
Systemic lupus erythematosus;
Trichinosis;
Pityriasis rubra pilaris;
Psoriasis; and
Renal failure.
Figure 22. Splinter hemorrhages tend to be fat.
Terry's Half and Half Nails
With Terry's half and half nails, the proximal
portion is white (edema and anemia) and the distal portion is dark.
These nails imply either renal or liver disease (Figures 23A, 23B).
Figure 23A. This example of Terry's half and half nails suggests liver disease (no brown lines).
Figure 23B. Half and
half nails imply renal disease when there is a brown band at the
junction of the erythema and the free edge. Image courtesy of www.dermnet.com Used with permission.
Generalized Discolorations of the Nail Plate
Nail discoloration is a useful method for identifying potential problems.
White Nails
White nails can be caused by anemia, edema, or vascular conditions (Figure 24). Consider the following:
Anemia;
Renal failure;
Cirrhosis;
Diabetes mellitus;
Chemotherapy; and
Hereditary (rare).
Figure 24. Example of white nails.
Pink or Red Nails
With pink or red nail discoloration, the following should be considered (Figure 25): Polycythemia (dark);
Systemic lupus erythematosus;
Carbon monoxide (cherry red);
Angioma; and
Malnutrition.
Figure 25. Example of pink and red nails.
Brown-Gray Nails
Brown-gray nails may suggest the following (Figure 26):
Cardiovascular disease;
Diabetes mellitus;
Vitamin B12 deficiency;
Breast cancer;
Malignant melanoma;
Lichen planus;
Syphilis; and
Topical agents, including hair dyes, solvents for false nails, varnish, and formaldehyde (among many others)
Figure 26. Example of brown-gray nails.
Yellow Nails
Yellow nails suggest the following (Figure 27):
Diabetes mellitus;
Amyloidosis;
Median/ulnar nerve injury;
Thermal injury; and
Jaundice.
Consider yellow nail syndrome if a patient has lymphedema and bronchiectasis.
Figure 27. Example of yellow nails. Image courtesy of www.dermnet.com Used with permission.
Green or Black Nails
Green or black nails indicate the following (Figure 28): Topical preparations, including chlorophyll derivations, methyl green, and silver nitrate (among others);
Chronic Pseudomonas spp infection; and
Trauma.
Figure 28. Example of black nails.
Processes Around the Nail
Paronychial Inflammation Paronychia
is associated with separation of the seal between the proximal nail
fold and the nail plate that provides entry for bacteria and leads to a
localized infection of the paronychial tissues of the hands (Figure
29). Symptoms may include inflammation, swelling, and/or scaling.
Figure 29. Example chronic paronychial inflammation.
Periungal Telangeictasia Periungal
telangeictasia is caused by dilated capillary loops and results in
atrophy of the cuticle (Figure 30). It is strongly associated with
collagen vascular disease, including the following:
Systemic lupus erythematosus;
Dermatomyositis (especially with Gotton's papules over knuckles); and
Scleroderma.
Figure 30. Example of periungal telangeictasia. Image courtesy of www.dermnet.com
Mucus Cyst A
mucous or myxoid cyst is a collection of degenerative collagen that can
cause swelling and ridging of the nail above the cyst, forming a
"gutter" (Figure 31).
Figure 31. Example of a mucus cyst.
Cases
The following are examples of patients in whom examining the fingernails may help identify their conditions.
Slide 1. 78-year-old with multiple conditions.
Slide 2. 84-year-old man with a painful ankle.
Slide 3. 68-year-old man with esophageal cancer.
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