Nail Disease

Nail Disease



Sharon Longshore Thornton, Kenneth J. Tomecki


The primary function of the nail is protection. Nail concerns are common, but the exact prevalence of nail disease is unknown. Nail disease occurs with certain skin diseases (psoriasis, eczema), often follows external trauma, may be an adverse effect of medication, and can occur with certain illnesses. The most common cause of nail disease is infection, usually fungal (onychomycosis) and less often bacterial. In many respects, the nails can indicate or reflect medical illness.



BASIC NAIL ANATOMY


The nail plate is a hard keratinized structure derived from keratinocytes within the nail matrix, which begins proximal to the nail plate and extends to the lunula, the white half-moon-shaped portion often seen through the nail plate. The proximal and distal nail matrices generate the dorsal and ventral nail plate, respectively. The nail bed beneath the nail plate extends from the lunula to the hyponychium, and the hyponychium lies under the free edge of the nail plate. The proximal and lateral nail folds compose the paronychium.



NAIL ABNORMALITIES AND SYSTEMIC DISEASE



Beau’s Lines


Beau’s lines (Fig. 1) are transverse depressions in the nail plate that often follow local trauma. They can reflect poor nutritional status, febrile illness, or a reaction to medication. Occasionally they occur with eczema, usually atopic or chronic hand eczema. Beau’s lines are a temporary cessation in nail growth and tend to appear about 1 month after the inciting event. Beau’s lines tend to resolve spontaneously by moving distally.


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Figure 1 Beau’s lines with transverse depressions in the nail plate.



Onycholysis


Onycholysis (Fig. 2) is the distal separation of the nail plate from the underlying nail bed. Onycholysis often occurs with thyroid disease, either hyperthyroidism or hypothyroidism, and commonly occurs with psoriasis and eczema. It can occur with porphyria cutanea tarda, lichen planus, eczema, and some of the autoimmune blistering diseases. It might also indicate an adverse reaction to medication, for example, tetracycline. Onycholysis may be persistent.


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Figure 2 Onycholysis with distal separation of the nail plate from the nail bed.



Onychomadesis


Onychomadesis is the proximal separation of the nail plate from the nail bed, which typically results in shedding of the nail. Trauma is the usual cause. Less common causes include poor nutritional status, febrile illness, or drug sensitivity. The inciting event causes complete cessation of nail matrix activity. Loss of the nail might or might not be permanent.



Onychorrhexis


Onychorrhexis (Fig. 3) is the presence of longitudinal striations or ridging of the nails. These striations can simply reflect advanced age, but they do occur in some patients with rheumatoid arthritis, peripheral vascular disease, lichen planus, or Darier’s disease. Longitudinal red and white striations invariably occur with Darier’s disease, and V-shaped notching or nicking of the free edges of the nails are also common. Onychorrhexis is usually persistent.


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Figure 3 Longitudinal ridging of the nails, or onychorrhexis.



Koilonychia


The spoon-shaped, concave nails of koilonychia (Fig. 4) commonly occur with iron-deficiency anemia and Plummer-Vinson syndrome, as a result of thinning and softening of the nail plate. Spoon-shaped nails are a normal physiologic occurrence in children. Koilonychia tends to resolve, either with treatment or with aging (children).


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Figure 4 Spoon-shaped nails of koilonychia.



Clubbing


Clubbing (Fig. 5) is an increase in the transverse and longitudinal nail curvature and fibrovascular hyperplasia of the soft tissue proximal to the cuticle. With clubbing, the angle (Lovibond’s angle) formed between the dorsal distal phalanx and the nail plate is increased. Clubbing often occurs with cardiopulmonary disease, for example, aortic aneurysm and bronchogenic carcinoma. The change is usually permanent.


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Figure 5 Increased nail curvature results in clubbing of the nails.



Splinter Hemorrhages


Splinter hemorrhages often follow trauma to the nail, but they classically occur in patients with bacterial endocarditis, less so in patients with rheumatoid arthritis, trichinosis, and renal disease, especially those on dialysis. Splinter hemorrhages represent extravasation of blood from the vessels of the nail bed. They can resolve, recur, or persist.



Leukonychia


Leukonychia (Fig. 6) is a white discoloration of the nail secondary to color change in the nail bed. Leukonychia includes Terry’s nails, half-and-half nails, and Muehrcke’s lines. Terry’s nails exhibit almost complete discoloration except for the distal edge; they occur most commonly with cirrhosis and congestive heart failure. The discoloration of half-and-half nails affects the proximal one half of the nail; they occur with chronic renal failure. Muehrcke’s lines (Fig. 7) are narrow white transverse lines (usually two); they occur with hypoalbuminemia. Mee’s lines resemble Muehrcke’s lines, but the lines are thicker and may be single or multiple. Mee’s lines occur with arsenic exposure.


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Figure 6 White discoloration of the nails, or leukonychia.


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Figure 7 Muehrcke’s lines associated with hypoalbuminemia.



Yellow Nail Syndrome


Yellow nail syndrome (Fig. 8) is a permanent cessation of nail growth resulting in hard, thickened, curved, yellow nails, occasionally with onycholysis. Yellow nails occur with lymphedema, chronic bronchitis, or bronchiectasis. Yellow nails tend to be persistent.


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Figure 8 Hard, thick, curved nails of yellow nail syndrome.



Pitting


Pitting (Fig. 9), or small punctate depressions in the nail plate, most commonly occurs with psoriasis, less so with alopecia areata and eczema. The pits represent abnormal keratinization in the nail matrix. In most cases, the treatment of skin disease has little if any effect on the nail disease.


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Figure 9 Punctate depressions in the nail plate, or pitting.

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Jul 18, 2017 | Posted by in GENERAL SURGERY | Comments Off on Nail Disease

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