SYMPTOMS.—There are no special subjective symptoms. The objective symptoms are the peculiar dark or black discoloration of the upper surface of the tongue and the excessively elongated filiform papillæ.
DIAGNOSIS.—The chief diagnostic feature is the black discoloration of the tongue which has given the name black tongue to the disease. Discrimination is requisite from discoloration by food or medicine.
PROGNOSIS.—This is favorable, the condition subsiding under treatment, and sometimes spontaneously, though liable to recurrence. In some instances the condition becomes chronic.
TREATMENT.—The indication is to endeavor to favor desquamation of the papilla by means of potassium chloride or sodium borate, and to administer alkalines, so as to render the saliva alkaline and unfavorable for the development of the parasite. It is recommended, in addition, to scrape the tongue with a spatula, and to douche it with a spray of mercuric chloride, 1:500. Attention to the general health is requisite, especially in dyspeptics and hypochondriacs. In the case of the negro child above alluded to the discoloration of the tongue finally disappeared under the systemic use of potassium iodide, without topical treatment, although repeated recurrences took place at varying intervals.
Parenchymatous Glossitis.
DEFINITION.—An inflammation of the tongue involving its substance as well as the mucous membrane.
SYNONYMS.—Idiopathic glossitis. Interstitial glossitis. Erectile glossitis (Salter), Glossomegistus (Sauvages), Paraglossia.
HISTORY.—Albeit a comparatively infrequent disease, especially at the present day, numerous cases and collections of cases are on record from very early times; and the affection seems to have attracted the attention of medical writers ever since. Hippocrates, Galen, Aretæus, Celsus, Aëtius, Avicenna, Forestus, Rivière, Schenkins, Sauvages, Vogel, van Swieten, are referred to by more modern writers as having described the disease. Louis, De la Malle, Lassus, J. P. Frank, Jn. Frank, Fleming,63 Clarke, and Bryant may be cited as the most prominent recent observers.
63 Dublin Journ. Med. Sci., 1850, vol. x.
ETIOLOGY.—Predisposing and Exciting Causes.—Glossitis is sometimes idiopathic, sometimes deuteropathic, and sometimes traumatic. Impaired health from over-fatigue or from exhaustive disease may be regarded as a predisposing cause in the presence of the causes which more frequently give rise to traumatic glossitis. Sudden or prolonged exposure to atmospheric changes, to cold and moisture, as when working in damp and wet localities, is often the apparent determining cause in both the idiopathic and deuteropathic varieties. In many instances occurring in this way it is found that the tongue has long been subjected to mechanical irritation from jagged teeth.