4. DISEASES OF THE NAILS
ONYCHAUXIS (Hypertrophy of the nail)
Definition. An excessive formation of the nail substance as regards length, breadth or thickness.
Symptoms. Hypertrophy of the nails may be congenital or acquired, symptomatic or idiopathic. One or all nails may partake of the change. Longitudinal increase has been noted to the extent of several inches, usually associated with a downward bend presenting all varieties of appearance between a claw-like curve and a ram’s horn spiral twist (onychogryphosis, curved nail). The nail substance is dirty yellow, brownish or grayish in color, ribbed or striated longitudinally or transversely, with its under surface flaky, brownish and marked by alternating ridges and depressions. Increased thickness in the substance of a nail presents a hard, thick, opaque, glossy or grayish-white appearance, generally curved upward or downward at the free border. The lateral hypertrophy is known as in growing nail, chiefly observed in the toes where a down-curving border may press deeply into the adjacent tissues, causing pain, tenderness, suppuration and granulation.
Inflammation of the tissue surrounding a nail is known as paronychia (whitlow) and it may occur independently of hypertrophic nail disease, often being produced by tight-fitting shoes or, when involving the hand, is found among those who are compelled to have their hands in water for a long time. Inflammation of the nail bed (onychia) may be secondary to hypertrophy of the nail, or primary, leading to atrophy or hypertrophy of the nail. The inflammation may be of a malignant type resulting from traumatism in a patient suffering from some grave chronic disease. It is often symptomatic of syphilis and, in recent years, it is associated with the constant use of even the weaker solutions of formalin (formalin onychia).
Disfigurement is not the only effect of these conditions. When the finger nails are affected, the sense of touch is diminished or destroyed and capacity for delicate work suffers; while if the toe nails are affected, walking may be difficult or rendered impossible.
Overgrowth of the nail-fold, known as pterygium, is shown in the abnormal downward growth of the fold of the skin that covers the proximal end of the nail, hiding the lunula. It may be freed from the nail by clipping or pushing back and is only mentioned here because often seen in the conditions just mentioned.
Etiology and Pathology. The congenital forms are rare and usually show a nail only relatively larger at birth but which continues to grow with undue rapidity. Acquired onychauxis is far more common and may arise from any of the following causes: trauma, the constant pressure of ill-fitting shoes, gout, rheumatism, chronic bone disease, degenerative or irritative neuroses, unrestrained growth as in the aged and bedridden through neglect, or in the Chinese by cultivation, lack of cleanliness, chronic inflammatory processes of the skin, such as psoriasis, eczema, syphilis, onychia, paronychia, occupation dermatoses, felon, lichen ruber, elephantiasis, leprosy and tuberculosis. However onychauxis need not develop unless predisposition to it exists because frequently the nails are not hypertrophied at all as a result of the above processes, and in some cases atrophy occurs from the identical conditions.
Many of the above factors lead to onychia but often it is idiopathic,a slight traumatism giving the opportunity for local pyogenic infection. Syphilis, tuberculosis and formation may be emphasized as occasional factors. Pressure and a variable amount of mild local pyogenic infection comprise the essential causes of paronychia.
Prognosis and Treatment. Relief or cure depends entirely upon the recognition of the causal factors. It is needless to say that in incurable conditions, normal nail growth is not to be expected. If the abnormality is curable, more or less relief of the local manifestation is possible.
The fundamentals of treatment embrace all physiological or constitutional measures directed toward the underlying condition. In aggravated cases with much involvement of the surrounding soft parts (paronychia), the latter may be removed by knife or scissors, under local anesthesia if necessary, and the wound allowed to heal by cicatrization, which contraction entirely frees the nail and often gives a good permanent result. When the hypertrophy is not pronounced, the nails need to be softened with hot sodium bicarbonate or borax solution, scraped thin in the center and the granulations destroyed under cocain with nitric acid or nitrate of silver. This is followed by the insertion of antiseptic gauze or lint between the edge of the nail and the skin, kept in place by adhesive plaster. In chronic cases without the ingrowing nail feature, oleate of tin (10 grains) or salicylic acid (30 grains) to the ounce of cold cream or lanolin, rubbed in and about the nail after the preliminary treatment, may prove beneficial. In distinctly suppurative cases of onychia or paronychia the X-rays will often be found advantageous. The acute stage of either disease may be successfully treated by Bier’s suction cups, and the application of 2 to 5 per cent. creolin in glycerin. Water should be avoided in these conditions and, except when absolutely necessary, the use of rubber gloves or cots should not be advised. General conditions and local lesions may call for any of the following: Cocculus, Fluor, acid, Graphites, Hepar, Hypericum, Kali mur., Lycopod., Nat. mur., N. sulph., Osmium, Phosphorus acid, Sarsaparilla, Silicea and Sulphur.