Page 216 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 7-5 Integumentary System

Onychogryphosis

COMMON NAIL DISORDERS
(Continued)

onycholysis (nail plate lifting off the nail bed). One nail
may be solitarily involved but it is more common for
several nails to be involved and for the surrounding
skin to be involved with tinea manuum or tinea
unguium. Fungal nail infections are much more fre-
quently seen on the toenails than on the fingernails.
The nails can become painful, especially with ambula-
tion. Occasionally, the entire nail is shed as a result of
significant onycholysis, and the nail that regrows will
again be involved with onychomycosis. The thick and
dystrophic nails may become a passage for bacterial
invasion of the body. This is especially true in patients
with diabetes. Bacteria can gain entrance into the skin
and soft tissue via the abnormal barrier between nail
and nail fold, and this can lead to paronychia, felon, and Correct Incorrect Ingrowing tissue Infected ingrowing tissue
the most serious complication, cellulitis. Distal and Pedicure
lateral subungual onychomycosis almost always needs
to be treated with an oral antifungal medication for any
chance of a cure. Topical agents may be helpful in Skin flap
limited nail disease, but their use is typically limited to Nail avulsed Proximal nail bed removed
an adjunctive role. Oral azole antifungals, griseofulvin, Distal Note the
and terbinafine have all been used, with similar results. nail bed proximity
Psoriasis can affect the nails in many ways. Nail of the
involvement appears more frequently in patients with nail bed
severe disease and in those with psoriatic arthritis. The to the
nails can show oil spots, pitting, ridging, onycholysis, underlying
and onychauxis (subungual hyperkeratosis). The oil bone.
spots are represented by a brownish to yellowish dis-
coloration under the nail plate and associated onycholy-
sis. The discoloration is caused by deposition of various
glycoproteins into the nail plate. Nail pitting can be Cotton pledget
seen in other conditions besides psoriasis, such as alo- under nail
pecia areata; it is caused by parakeratosis of the proxi-
mal nail matrix, which is responsible for producing the
dorsal nail plate. Ridging and onychauxis is caused by
the excessive hyperkeratosis of the nail bed, which is
directly caused by psoriasis. Therapy for psoriatic nails Removal of one
can involve intralesional steroid injections or use of third of nail bed
systemic agents to decrease the abnormal immune
response that is driving the psoriasis.
Onychogryphosis (“ram’s horn” nail deformity) man-
ifests with an unusually thickened and curved nail that
takes the shape of a ram’s horn.
A plethora of nail changes may be seen in response Suture of
to systemic disease. Beau’s lines are horizontal notches skin flap
along the nails that may be caused by any major stressful
event. The stressful event typically is induced by pro-
longed hospitalization, which causes temporary inade-
quate production of the nail bed by the nail matrix. It plate and bed appear dull white with loss of the lunula. Koilonychia is one of the most easily recognized defor-
is entirely corrected spontaneously as the individual Half-and-half nails, also called Lindsay’s nails, are seen mities of the nail; it is caused by iron deficiency. The
improves. Mees’ lines are induced by heavy metal toxic- in patients with chronic renal failure. The proximal half nail plate develops a spoon-shaped, concave surface.
ity, most commonly from arsenic exposure. They of the nail is normal appearing, whereas the distal half Splinter hemorrhages may be a sign of bacterial endo-
appear as a single, white horizontal band across each has a brown discoloration. Yellow nail syndrome mani- carditis. Clubbing, which is defined as loss of Lovi-
nail. Mees’ lines have also been reported in cases of fests with all 20 nails having a yellowish discoloration bond’s angle, is typically caused by chronic lung disease.
malnutrition. Terry’s nails is the name given to nail and increased thickness of the nail plate. This syndrome The nail unit can manifest disease in many ways, and
changes seen in congestive heart failure and cirrhosis of is almost always seen in association with a pleural effu- awareness of the various nail signs can help the clinician
the liver: More than two thirds of the proximal nail sion, often secondary to a lung-based malignancy. diagnose and treat these conditions.

202 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS